Objectives. Previous attempts at obtaining population estimates of human immunodeficiency virus type 1 (HIV-1) seroprevalence have been beset by problems of cooperation bias. As part of the fourth round of study with an urban African-American community cohort, the following investigation was aimed at assessing HIV-1 prevalence and the relative importance of sex and drug injection as risk factors in infection. Methods. Personal interviews were conducted in the home with 364 respondents, followed by voluntary blood sample collection from 287 of these individuals. Results. Blood assays showed a point prevalence of 8.4% HIV-1 seropositivity in this community cross section, with a higher female-to-male ratio than appears among acquired immunodeficiency syndrome (AIDS) case reports. Most infected persons were unaware and unsuspecting of their infection. Conclusions. First, findings underscore the need to focus on risk behaviors rather than on risk groups. Second, the smaller than 2:1 ratio of infected men to women suggests that current AIDS case reports seriously underestimate HIV-1 infection among certain cohorts of African-American women. Finally, wide spread ignorance of own infected status and inaccurate risk assessment signal the substantial task for community health educators in reaching inner-city African-American men and women at risk.