Previous studies have shown that a subset of gay, lesbian, and bisexual (GLB) and heterosexual adults produce distinctive patterns of phonetic variation that allow listeners to detect their sexual orientation from audio-only samples of read speech. The current investigation examined the extent to which judgments of sexual orientation from speech are related to judgments of masculinity or femininity made by an independent group of listeners. It also examined the acoustic measures that predict perceived sexual orientation and perceived masculinity/femininity. Ten listeners judged the perceived masculinity or femininity of 44 talkers (11 heterosexual men, 11 heterosexual women, 11 gay men, and 11 lesbian or bisexual women). These were compared to measures of the talkers' perceived sexual orientation, and to acoustic measures of the talker's speech. Listeners judged gay men to sound less masculine than heterosexual men, and lesbian/bisexual women to sound less feminine than heterosexual women. These measures were significantly correlated with measures of perceived sexual orientation. Regression analyses showed that different sets of acoustic measures predicated perceived sexual orientation and perceived masculinity/femininity, and that some acoustic measures were more strongly correlated with one perceptual measure than the other. Results suggest that perceived sexual orientation, perceived masculinity, and perceived femininity are distinct but correlated perceptual parameters. (Contains 1 table, 2 figures, and 2 footnotes.)