Part I of this article, which appeared in the previous issue of Family Planning Perspectives, reviewed the scientific literature on the effects of barrier methods and spermicides (used alone or in combination with a barrier method) on infection with sexually transmitted diseases (STDs). In general, recent studies have concluded that condoms used alone, spermicides used alone and methods combining mechanical barriers with spermicides all provide protection against STDs. Part II reviews what is known about the effects of the pill, the IUD, tubal sterilization and abortion on the risks of upper reproductive tract infections. A discussion of the trade-offs involved in choosing a contraceptive is illustrated by estimates of the first-year rates of unplanned pregnancy and gonorrhea infection (given an infected partner) among women using various contraceptive methods. As in part I, studies summarized in the tables are arranged by increasing strength of study design. In general, descriptive or cross-sectional designs are the most vulnerable to methodologic problems; case-control studies, cohort investigations and randomized clinical trials follow, in ascending order of strength.