She was born in 1914 in Kunjah, Punjab now in Pakistan, and came to Delhi in her youth to study medicine at Lady Hardinge Medical College. In 1939 she came to Sevagram to join her brother, and quickly became a close associate of the Gandhis. Shortly after her arrival, cholera broke out in Wardha, and the young medical graduate tackled the outbreak almost singlehandedly. Gandhi praised her fortitude and dedication to service, and with the blessing of Dr B.C. Roy appointed her as his personal physician. In 1942 she was awarded an MD and returned once more to Gandhi's side, to take part in the Quit India Movement that was sweeping the country. That year she was imprisoned along with other prominent Gandhians at the Aga Khan Palace in Poona.
In 1944 she set up a small dispensary at Sevagram, but this soon grew so large it disturbed the peace of the ashram, and she shifted it to a guesthouse donated by the Birlas, in Wardha. In 1945 this little clinic formally became the Kasturba Hospital (now the Mahatma Gandhi Institute of Medical Sciences). This time was, however, highly fraught; several attempts were made on Gandhi's life by Hindu extremists, including Nathuram Godse, the man who was ultimately to kill him, and Sushila Nayyar testified on several occasions to the attacks. In 1948 she appeared before the Kapur Commission regarding the incident in Panchgani in 1944 when Nathuram Godse allegedly tried to attack Gandhi with a dagger.
After Gandhi's assassination in 1948 in Delhi, Sushila Nayyar went to the USA where she took two degrees in public health from the Johns Hopkins School of Public Health. Returning in 1950, she set up a tuberculosis sanatorium in Faridabad, the model township on the outskirts of Delhi set up on cooperative lines by fellow Gandhian Kamaladevi Chattopadhyay. Nayyar also headed the Gandhi Memorial Leprosy Foundation.
In 1952 she entered politics and was elected to the Legislative Assembly of Delhi. From 1952 to 1955 she served as Health Minister in Nehru's cabinet. She was Speaker of the Delhi Vidhan Sabha (as the State Assembly had been renamed) from 1955 to 1956. In 1957 she was elected to the Lok Sabha and served till 1971. She was Union Health Minister again from 1962 to 1967. During the congress regime, she fell out with Indira Gandhi and was member of the opposition (Janata party). She briefly held a position when it was voted to power that created history by overthrowing Indira Gandhi's government. Thereafter she retired from politics to devote herself to the Gandhian ideal. She had set up the Mahatma Gandhi Institute of Medical Sciences in 1969, and remained committed to confine her energies to developing and extending it. She died on 3rd January 2000, due to cardiac arrest.
Sushila Nayyar was deeply influenced by the Navajivan Publishing House.)