The 1991 National Survey of Men (NSM-I) was conducted between March 1991 and January 1992, under a grant from the National Institute of Child Health and Human Development, to examine issues related to sexual behavior and condom use among a national household probability sample of males aged 20-39. The NSM-I was intended to serve as the baseline survey for a longitudinal study of this group of U.S. men. Data collection and processing were carried out by the Institute for Survey Research at Temple University in Philadelphia. In-person interviews were conducted using a standard questionnaire with 3,321 eligible males.

The survey questionnaire assessed information regarding respondents' personal background; sexual initiation and current exposure; current wife or partner; previous marital relationships; non-marital sexual partners; nonsexual romantic partners; health and risktaking behavior; attitudes, perceptions and knowledge regarding health and contraception; and condom use. A self-administered questionnaire, which assessed self-esteem, locus of control, and attitudes toward marriage, was also completed by respondents.