Sexual dysfunction is so highly prevalent in elderly males that it is often considered an inevitable consequence of "normal aging." To determine if other factors are related to an age-associated decline in sexual function, we surveyed two groups of elderly male veterans in a geriatric ambulatory care clinic: aged 65 to 75 years ("young-old") and aged over 75 ("old-old"). We compared their survey responses with responses from a general medical clinic for unstable medical patients, aged under 65 ("old-young"). Of 347 subjects surveyed, 225 completed a health and sexual function questionnaire (response rate = 65%). Absent libido was reported by 30% of old-young, 31% of young-old, and 47% of old-old. Erectile dysfunction was reported in 26% of old-young, 27% of young-old, and 50% of old-old (P less than .01). We used ordinal logistic regression and found overall sexual dysfunction to be significantly related to subjective poor health, diabetes mellitus, and incontinence (P less than .05), while controlling for age. These data suggest that, although sexual dysfunction is more common in the aged, it is often related more to comorbid illness than aging alone.