The success of a compulsory sterilization programme depends on obtaining a correct history of family size from the couples concerned. Accordingly, we carried out a feasibility study at Prabhadevi Municipal Hospital, Bombay. At registration for confinement the women were required to produce some documentary proof such as a ration card, Employee's State Insurance Scheme card, or a letter from the Sarpanch of Gram Panchayat for women coming from villages, to indicate the number of their living children. The difficulties met by the staff in obtaining the necessary information and the problems of the women in providing documentary evidence are discussed, together with the results of the survey.