This volume contains the papers on family planning research which were presented at the XIth World Congress on Fertility and Sterility held in Dublin, Ireland in June, 1983 under the auspices of the International Federation of Fertility Societies. These papers were presented during the related communications sessions of the Congress and have been brought together into a special volume which will be of major interest to those concerned with family planning. Section 1, deals with the area of natural family planning, determination of the fertile period and effects of lactation. Steroid contraception, vaginal and intrauterine contraception, abortion and sterilization are included in Sections 2-4. Social aspects of fertility control are covered in Section 5 and the final section contains studies of the effects of gossypol as a male contraceptive. This volume brings together important new knowledge in the area of family planning, clarifies some of the problems and should stimulate research on the many unresolved issues in this vitally important area.