Investigated the adverse sexual effects of two antihypertensive drugs, atenolol and slow-release nifedipine, in a placebo-controlled, randomized, crossover study. Subjects were 16 older men (mean age = 66.6 years, SEM = 1.4) with mild to moderate hypertension. Subjects completed daily self-reports on 13 measures of sexuality: frequency of desire, coitus, noncoital partner sex, masturbation, morning erections, spontaneous erections, orgasms in coitus and masturbation, firmness of morning, masturbatory and coital erections, and subjective pleasure in coitus and masturbation. Except for a significant decrease in masturbatory erectile firmness with nifedipine therapy, variables did not differ between the two drug treatments or between either drug and placebo. Although the sample was relatively small, small differences between treatment means suggest that these antihypertensive agents are fairly benign relative to sexual function in men.