This is the second of two reports of a National Institute for Occupational Safety and Health (NIOSH) Health Hazard Evaluation conducted in response to complaints of sexual dysfunction among men who manufacture the stilbene derivative 4,4'-diaminostilbene-2,2'-disulfonic acid (DAS; CAS 81-11-8), an intermediate in the manufacture of fluorescent whitening agents. The first report [Grajewski et al. (1995): Am J Ind Med 29:53-61] describes results of the analysis of reproductive hormone levels. This second report provides results from the analysis of perceived libido and potency. In a cross-sectional design, self-reported sexual function of 30 male workers who manufacture DAS and 20 former DAS workers was compared to that of 35 workers who manufactured plastics additives in a different manufacturing area. Questionnaire items were examined by factor analysis, reducing the data to these components of sexual function: sexual activity/performance (two factors), interest, satisfaction, and physiologic competence. Adjusting for age, currently exposed workers were more likely than unexposed workers to have a value in the lowest quartile for interest (adjusted odds ratio [OR] = 1.9, 95% confidence interval [CI] 0.5-7.2), physiologic competence (adjusted OR = 1.9, 95% CI 0.6-6.4), and activity/performance factor II (adjusted OR = 5.8, 95% CI 1.3-27.3). Former DAS workers reported problems associated with activity/performance factors I and II compared to unexposed workers (adjusted OR = 2.2, 95% CI 0.5-10.1 and adjusted OR = 6.7, 95% CI 1.2-35.9, respectively). Although the small study size limits the precision of the effect estimates, the pattern of results suggests a possible effect on sexual function of working in the DAS manufacturing area.