The purpose of this study was to learn about the frequency of sexual disorders in young males who later become substance abusers. We interviewed 228 men treated in 10 drug centers for substance abuse. The questionnaire that we used was designed to assess the onset of erectile dysfunction (ED) or of premature ejaculation (PE). Only those subjects who became substance users between the ages of 17 to 29 were taken into consideration. Of the 228 subjects recruited, only 130 met the inclusion criteria (mean age 33). These male patients had a prevalence of ED of 20.3% (cl 99% 12.3-31.2), whereas the prevalence of ED of age-matched males in the general population is 2.1% (cl 99% 0.36-5.46; p < 0.000001). The prevalence of PE in the sample prior to drug use was 37.5%. Sexual desire was in the normal range in nearly all subjects. The prevalence of ED in the men of our sample is higher than in age-matched individuals of the general population. These data suggest a new hypothesis: sexual disorders or the conviction that one has a sexual problem is a possible risk factor among men for drug abuse and addiction.