Very high levels of alcohol consumption during pregnancy are harmful for the central nervous system of the child and affect morphogenesis and growth. The aim of this study was to investigate the effects of moderate prenatal alcohol exposure on development at preschool age in a longitudinal study. Pregnant women were interviewed on their alcohol consumption during pregnancy at their first visit to the maternity hospital of Roubaix, France. The development of their 160 children was assessed at the age of 4 1/2. Multiple regression analyses indicated that consumption of 1.5 oz of absolute alcohol (approximately 3 drinks) or more during pregnancy was significantly related to a decrease of 7 points on the general cognitive index of the McCarthy scales, after controlling for confounders. This level of consumption was also related to a higher score on minor neurological anomalies, a lower height of the child, and a higher score on facial features. This level of 1.5 oz of absolute alcohol/day should not be interpreted as a biological threshold, because the study does not allow conclusions to be drawn regarding the effects of lower levels of alcohol consumption. Alcohol consumption during pregnancy can affect the development of the child, at levels well below those associated with fetal alcohol syndrome.