Relations between sexual orientation and several biodemographic variables previously reported to differentiate between homosexual and heterosexual men were examined. Subjects were 4948 white, postpubertal males, who were never reared in foster homes, orphanages, or other institutions, and were never arrested or convicted on criminal charges. These were dichotomously classified as homosexual (n = 844) or heterosexual (n = 4104). Data came from survey interviews conducted by staff members of The Kinesey Institute for Research in Sex, Gender, and Reproduction from 1938 to 1963. Results extended previous findings that, compared with heterosexual controls, homosexual men have a later birth order, an earlier onset of puberty, and a lower body weight. Sexual orientation was weakly related or unrelated to height, paternal age, and sibling sex ratio. A more detailed analysis of the late birth order of the homosexual group showed that homosexual men have a greater number of older brothers than do heterosexual men, but they do not have a greater number of older sisters, once their number of older brothers has been taken into account.