Approximately 13.3 million women aged 15-44--about 26 percent of all women of reproductive age who had ever had intercourse--were tested for sexually transmitted diseases (STDs) in the 12 months before the 1988 National Survey of Family Growth. Slightly over half of the women tested received the test as part of a family planning visit. Women who used clinics for family planning services were most likely to be tested--54 percent compared with 34 percent of women who used a private doctor for family planning and 16 percent of women who did not receive family planning services that year. The findings suggest that access to medical care, especially access to family planning clinics, has strong effects on a woman's chances of being screened for STDs, independent of her individual characteristics. The most important individual characteristic affecting the chance of being tested for an STD was race: About 47 percent of black, 27 percent of Hispanic, and 23 percent of white and other women were tested in the 12 months before the survey. Among groups with high-risk behaviors, only 34 percent of sexually experienced teenagers were screened for STDs in the past year, as were only 43 percent of women with a positive STD history and 32 percent of women with 10 or more lifetime partners.