Decades of research have indicated the foundational importance of parenting to offspring outcomes during childhood and beyond. Unearthing the specific origins of parenting is therefore a critically important research objective. Extant research on this topic has suggested that parenting behaviors are multidetermined (Belsky, 1984) and are associated with a wide range of contextual and familial characteristics (e.g., ethnicity, community, family financial stress), as well as characteristics of the parents (e.g., personality) and their children (e.g., temperament). Behavioral genetic studies have further indicated that parenting behaviors are in fact heritable-that is, individual differences in parenting are at least partially a function of genetic differences between persons. Critically, however, the estimates of these genetic influences have varied dramatically across studies. It is also unclear how factors such as parent gender, child age, and methodological considerations may impact genetic influences on parenting behavior. In the current set of meta-analyses, we sought to quantitatively synthesize twin and adoption studies (n = 56) examining the etiology of parenting behavior, with the goal of more definitively cataloguing genetic and environmental effects on parenting. Results reveal significant effects of parental genetic makeup on parental behavior, but also highlight the genetic makeup of the child as a particularly prominent source of genetic transmission (via evocative gene-environment correlation). Environmental contributions to parenting also emerged as important, including both shared and nonshared environmental effects. Theoretical implications of these findings are discussed.