OBJECTIVE: To determine if heterosexual and nonheterosexual men treated for prostate cancer differ in diagnostic and treatment outcomes and in various measures of physical health, sexual function, and well being, before and after the treatment. METHODS: Four hundred sixty self-identified heterosexual and 96 self-identified nonheterosexual men completed an anonymous online survey. The men in the 2 groups were then compared using logistic regressions that controlled for differences among countries. RESULTS: There were no significant differences in age at diagnosis for men in the 2 groups. However, Gleason scores at diagnosis were significantly lower for the nonheterosexual men (P = .02). There were no significant differences among men in the 2 groups in the proportion who receive different treatment modalities or in the incidence of urinary incontinence, who experience bone pain (as a marker of disease progression), who take antidepressants (as a proxy measure for mental health), or who experience erectile dysfunction after the treatment. However, nonheterosexual men rated the degree to which they were bothered by an inability to ejaculate significantly higher than did the heterosexual men (P = .04). CONCLUSION: This is the first set of findings from a survey that compares heterosexual and nonheterosexual men treated for prostate cancer. Although the groups were generally similar, nonheterosexual men might experience more intensive screening for disease, as indicated by lower Gleason scores at diagnosis. Nonheterosexual men appear more distressed by loss of ejaculation after prostatectomy.