The Bowery series, open perineal biopsies performed on more than 1200 alcoholic men recruited from homeless shelters in New York City's Bowery section, began in 1951 and persisted for more than a decade. If frozen sections revealed prostate cancer, men typically underwent radical perineal prostatectomy, orchiectomy, and diethylstilbestrol treatment. This poorly informed, vulnerable population was subjected to health risks that investigators knew others would not accept. Although the knowledge produced had little impact on practice, the Bowery practices foreshadowed and have troubling continuities with later developments. Currently, more than a million American men each year undergo prostatic biopsies. But the efficacy of prostate-specific antigen screening and the treatment that typically follows has never been established. The Bowery series and subsequent developments are part of one continuous story of how medical and lay people came to believe in the efficacy of population screening followed by aggressive treatment without solid supporting scientific evidence.