The women were age 18 and over interviewed by carefully selected and trained female interviewers during the summer of 1978. Sixteen percent of the women reported at least one experience of intrafamilial sexual abuse before age 18, and 31 percent reported at least one experience of extrafamilial sexual abuse before age 18. Combining both categories showed that 38 percent had been abused before age 14. Only 2 percent of the intrafamilial cases and 6 percent of the extrafamilial cases were ever reported to the police. The abuse ranged from nonforceful kissing to forcible rape. These alarming prevalence rates point to the need for measures to address the problem and to develop more effective prevention strategies. Tables and 27 reference notes. (Author abstract modified)