Bidhan's mother passed away when he was 14. His father played the role of both father and mother to his five children. He promised never to compel them to do anything but to just guide them on their path. All five children were required to do the household chores themselves. This was very helpful for Bidhan in his college days.

Bidhan did his B.A. from Patna College with Honors in Mathematics. He applied for admission to the Sibpur Engineering College and the Calcutta Medical College. He was accepted to both institutions but opted to go to medical school. Bidhan left for Calcutta in June 1901. While at medical school Bidhan came upon an inscription which read, "Whatever thy hands findeth to do, do it with thy might." Bidhan was deeply impressed by these words and they became a source of inspiration for him throughout his life.

Bidhan's term in medical school was fraught with hardships. His father retired as a Deputy Collector after the first year and could no longer send Bidhan any money. Bidhan fended for himself by getting a scholarship and living frugally, saving on books by borrowing notes and relying on books in the library.

The partition of Bengal was announced while Bidhan was in college. Opposition to the partition was being organized by nationalist leaders like Lala Lajpat Rai, Arvinda Ghosh, Tilak and Bipin Chandra Pal. Bidhan resisted the immense pull of the movement. He controlled his emotions and concentrated on his studies realizing that he could better serve his nation by qualifying in his profession first.

Immediately after graduation, B.C. Roy joined the Provincial Health Service. He exhibited immense dedication and hard work. He was prepared to prescribe medicine to patients and even serve as a nurse when necessary. In his free time he practiced privately, charging a nominal fee of Rs. 2 only.

Bidhan sailed for England with only Rs. 1,200 in February of 1909 intending to enroll himself at St. Bartholomew's to further his education. The Dean, reluctant to accept a student from Asia, rejected Bidhan's application. Dr. Roy did not loose heart. Again and again he submitted his application until finally the Dean, after 30 admission requests, accepted Bidhan to the college. Within two years and three months, Bidhan completed his M.R.C.P and F.R.C.S and returned home from England in 1911. On his return he taught at the Calcutta Medical College, then the Campbell Medical School and finally at the Carmichael Medical College.

Dr. Roy believed that swaraj would remain a dream unless the people were healthy and strong in mind and body. He made contributions to the organization of medical education. He established the Jadavpur T.B. Hospital, Chittaranjan Seva Sadan, R.G. Khar Medical College, Kamala Nehru Hospital, Victoria Institution, and Chittaranjan Cancer Hospital. The Chittaranjan Seva Sadan for women and children was opened in 1926. The women were unwilling to come to the hospital initially but thanks to Dr. Roy and his teams hard work, the Seva Sadan was embraced by women of all classes and communities. He opened a center for training women in nursing and social work.

In 1942, Yangon fell to Japanese bombing and caused an exodus from Calcutta fearing Japanese insurgency. Dr. Roy was serving as the Vice-Chancellor of the University of Calcutta. He acquired air-raid shelters for schools and college students to have their classes in, and provided relief for students, teachers and employees alike. In recognition for his efforts, the Doctorate of Science was conferred upon him in 1944.

Dr. Roy believed that the youth of India would determine the future of the nation. He felt that the youth must not take part in strikes and fasts but should study and commit themselves to social work. At his Convocation Address on December 15, 1956 at the University of Lucknow, Dr. Roy said, "My young friends, you are soldiers in the battle of freedom-freedom from want, fear, ignorance, frustration and helplessness. By a dint of hard work for the country, rendered in a spirit of selfless service, may you march ahead with hope and courage... ."

Dr. Roy was both Gandhiji's friend and doctor. When Gandhiji was undergoing a fast in Parnakutivin, Poona in 1933 during the Quit India Movement, Dr. Roy attended to him. Gandhiji refused to take medicine on the grounds that it was not made in India. Gandhiji asked Dr. Roy, "Why should I take your treatment? Do you treat four hundred million of my countrymen free?" Dr. Roy replied, "No Gandhiji, I could not treat all patients free. But I came... not to treat Mohandas Karamchand Gandhi, but to treat "him" who to me represents the four hundred million people of my country." Gandhiji relented and took the medicine.

Dr. Roy entered politics in 1925. He ran for elections from the Barrackpore Constituency as an Independent candidate for the Bengal Legislative Council and defeated the "Grand Old Man of Bengal," Surendranath Banerjea. Even though an independent he voted with the Swaraj Party (the Parliamentary wing of the Congress). As early as 1925, Dr. Roy tabled a resolution recommending a study of the causes of pollution in Hoogly and suggested measures to prevent pollution in the future.

Dr. Roy was elected to the All India Congress Committee in 1928. He kept himself away from rivalry and conflicts and made a deep impression on the leaders. Dr. Roy efficiently conducted the Civil Disobedience in Bengal in 1929 and prompted Pandit Motilal Nehru to nominate him Member of the Working Committee (CWC) in 1930. The CWC was declared an unlawful assembly and Dr. Roy along with other members of the committee were arrested on August 26, 1930 and detained at Central Alipore Jail.

During the Dandi March in 1931, many members of the Calcutta Corporation were imprisoned. Congress requested Dr. Roy to remain out of prison and discharge the duties of the Corporation. He served as the Alderman of the Corporation from 1930-31 and Mayor in 1933. Under him, the Corporation made leaps in the expansion of free education, free medical aid, better roads, improved lighting, and water supply. He was responsible for setting up a framework for dispensing grant-in-aid to hospitals and charitable dispensaries.

The Congress Party proposed Dr. Roy's name for Chief Minister of Bengal. Dr. Roy wanted to devote himself to his profession. On Gandhiji's advice, however, Dr. Roy accepted the position and took office on January 23, 1948. Bengal at the time had been torn by communal violence, shortage of food, unemployment and a large flow of refugees in the wake of the creation of East Pakistan. Dr. Roy brought unity and discipline amongst the party ranks. He then systematically and calmly began to work on the immense task in front of him. Within three years law and order was returned to Bengal without compromising the dignity and status of his administration. He told the people,

"We have the ability and if, with faith in our future, we exert ourselves with determination, nothing, I am sure, no obstacles, however formidable or insurmountable they may appear at present, can stop our progress... (if) all work unitedly, keeping our vision clear and with a firm grasp of our problems."

The nation honored Dr. Roy with the Bharat Ratna on February 4, 1961. On July 1, 1962, after treating his morning patients and discharging affairs of the State, he took a copy of the "Brahmo Geet" and sang a piece from it. 11 hours later Dr. Roy died. He gifted his house for running a nursing home named after his mother, Aghorkamani Devi. The B.C. Roy National Award was instituted in 1976 for work in the area of medicine, politics, science, philosophy, literature and arts. The Dr. B.C. Roy Memorial Library and Reading Room for Children in the Children's Book Trust, New Delhi, was opened in 1967