A wide variety of perinatal risk factors have been linked to later developmental outcomes children. Much of this work has relied on either birth/medical records or mothers’ self-reports collected after delivery, and there has been an ongoing debate about which strategy provides the most accurate and reliable data. This report uses a parent-offspring adoption design (N = 561 families) to (1) examine the correspondence between medical record data and self-report data, (2) examine how perinatal risk factors may influence child internalizing and externalizing behavior at age 4.5 years, and (3) explore interactions among genetic, perinatal risk, and rearing environment on child internalizing and externalizing behavior during early childhood. The agreement of self-reports and medical records data was relatively high (51–100%), although there was some variation based on the construct. There were few main effects of perinatal risk on child outcomes; however, there were several 2- and 3-way interactions suggesting that the combined influences of genetic, perinatal, and rearing environmental risks are important, particularly for predicting whether children exhibit internalizing versus externalizing symptoms at age 4.5 years.