Cervical caps are small cuplike diaphragms placed over the cervix. They are supposed to be held in place by suction. To provide a successful barrier against sperm, they must fit tightly over the cervix. Because of variability in cervical size, individualization is almost essential. This greatly limits the practical usefulness of the method. Tailoring the cap to fit each cervix is difficult. In addition, many women are unable to feel their own cervix and thus have great difficulty in placing the cap correctly over the cervix. Because of these problems, the cervical cap has few advantages over the traditional vaginal diaphragm. Although some advocates of the cervical cap recommend that it remain in place for 1 or 2 days at a time, a foul discharge often develops after about 1 day’s use. With proper use, the efficacy of the cervical cap is similar to that of the diaphragm, with dislodgment being the most frequently cited cause of failure in most reports. In any event, due to the difficulty associated with proper fitting and routine insertion, it is doubtful that the cap in its present state of development will play an important role in contraception.