Because it appeared that prior surveys all suffered from underdisclosure of sexual assault experiences, this study was designed to encourage full disclosure. The interview schedule was carefully worded to help create good rapport with the respondent, and interviewers were selected for their sensitivity to the issue of sexual assault as well as for their interviewing skills. To facilitate comparisons with the official statistics on rape as well as with those reported in other studies, the legal definition of rape used in most States as of 1978 (when the study was conducted) was employed: attempted or completed intercourse by force, threat of force, or when the person is unable to consent because she or he is unconscious, drugged, or in some other manner totally helpless. The study applied the life-table analysis methodology used by Johnson to the age-specific rape rates found in this study, so that the results can be compared to Johnson's. In concluding that at least a 46 percent probability exists for San Francisco women to experience a completed or attempted rape in their lifetime, it was assumed that the rape rate will remain the same; however, there has been a 6 percent increase in the rape rate between 1979 and 1980 and a 38 percent increase since 1976. These findings support Johnson's conclusion that 'sexual violence against women is part of the everyday fabric of American life.' Tabular data and 24 footnotes are provided.