The present study assessed the magnitude of sex differences in loneliness after accounting for the influence of two covariates: masculinity and femininity. The 256 participants (principally White, somewhat affluent, and middle-class university students) completed both the UCLA Loneliness Scale and the Bem Sex Role Inventory. Whereas sex differences were originally nonsignificant (males tended to be lonelier than females), this difference was significant after accounting for masculinity (not femininity) embedded in participants' loneliness scores. Similar results emerged when the covariates were partialled out of both loneliness (criterion) and sex (predictor). These findings support the hypothesis that males appear reluctant to admit feelings of loneliness. Male reluctance to personally admit social deficits such as loneliness is suggested for future research.