Oral contraceptive (OC) use and alcohol consumption have been shown to alter the levels of lipids and lipoproteins in the blood. The effect of alcohol consumption on levels of total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, LDL-B, Apo-A1, the ratio of HDL cholesterol/total cholesterol, HDL cholesterol/LDL cholesterol, and the ratio of LDL cholesterol/LDL-B among normal healthy young women before initiation of oral contraceptives and after six months of oral contraceptive use are both described. Of primary interest is the mediating effect of alcohol consumption on the association between steroid usage and blood lipid values. At baseline, ethanol consumption was found to be positively associated with triglycerides, HDL-C, and Apo-A1 and negatively associated with LDL-C/LDL-B. After adjustment for several covariables, alcohol consumption was found to be positively associated with the increases in triglycerides and in Apo-A1 observed at 3 and 6 months after initiation of OCs. Since these two parameters are believed to have opposite relationships to cardiovascular disease, the effect of alcohol consumption remains uncertain.