This study examined pubertal maturation, pubertal timing and outcomes, and the relationship of puberty and sexual identity developmental milestones among 507 lesbian, gay, and bisexual youth. The onset of menarche and spermarche occurred at the mean ages of 12.05 and 12.46, respectively. There was no statistically significant difference in perceived timing of puberty by sex compared to peers. Males were more likely to react positively to the perception that the timing of puberty was earlier than their peers. Earlier menarche was associated with increased externalizing problems, but earlier spermarche was not related to internalizing or externalizing problems. Age of spermarche was associated with the ages of sexual identity milestones in males but not in females.