Objective. This meta-analysis integrates the available empirical evidence of the past 35 years and critically discusses the current state of knowledge on children raised by gay or lesbian parents. Design. Data from 81 studies on children living with gay or lesbian parents and opposite sex couples was included in the analyses. Results. There were negative associations between living with gay or lesbian parents and several outcomes. Most outcomes showed significant variation across studies and were treated as random effects. There appeared to be evidence consistent with publication bias. Significant moderators included child age, environmental stability, adequacy of heterosexual comparison sample, sampling technique, sample location, researcher allegiance, citation rate, and publication status. Conclusions. Future research on this topic is needed, consisting of adequately-powered probability-based samples, with detailed measurement and safeguards against researcher bias.