The aim of this study was to evaluate whether maternal diabetes in pregnancy may adversely affect the children's behavioral adjustment, in a sample of 201 mothers (68 with pre-gestational diabetes, 50 with gestational diabetes, and 83 with non-diabetic pregnancies) and their singleton offspring. After accounting for socioeconomic status, ethnicity and maternal attitudes, none of the Child Behavior Checklist ratings correlated significantly with maternal patient group or several indices of antepartum maternal metabolism. Child obesity, a common sequela of diabetic pregnancies, correlated positively with Internalizing Behavior problems and three narrow-band sub-scales: Somatic Complaints, Anxious/Depressed, and Social Problems. Results suggest that children of diabetic mothers are at increased risk for a variety of developmental disturbances. Screening for learning and behavioral difficulties should be made at regular pediatric visits, with follow-up evaluations warranted by positive indications, excessive weight gain, or other evolving medical concerns.