In nearly 2,000 intercourses 14 different types of condoms were tested by 80 heterosexual and seven homosexual volunteer couples. The test couples were generally quite experienced in the use of condoms. It appears that the condoms rarely (1.3%) ruptured or slipped off during the actual intercourse. This means that emphasis must be put on consistency and skill in the use of condoms rather on technical improvements in the promotion of condoms as a means of preventing the spread of sexually transmitted infections like HIV. Lubricated condoms and condoms that were not too small were preferred by both users and their partners. Other condom properties were significant but of minor concern for the participants of the study.