A retrospective analysis utilizing historical data collected as part of our computerized data base was performed to assess the impact of marijuana use in pregnancy on pregnancy outcome. Records of 8350 patients were reviewed and 417 patients gave a history of only marijuana use for a prevalence of 5%. There was no association between marijuana use and prematurity or congenital anomalies. Marijuana use was strongly associated with the use of alcoholic beverages and smoking. Previously reported associations may represent the concomitant use of these other drugs.