Abstract: The effects of gender and alcohol consumption on serum enzymes, protein and bilirubin in heavy, moderate and non-drinkers were investigated. Seven-two healthy human subjects were divided equally into males and females. They were categorized as heavy, moderate and non-drinkers, using carefully structured questionnaires. Whole blood was taken via puncture of the cubical vein and serum protein, albumin, total and direct bilirubin concentrations were determined using Synchron CX 5 autoanalyzer. The activities of serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and gamma glutamyl transferase were assayed. The age and body mass index of the males and females were 45.60±1.80 years, 22.16±0.83 kg m-2 and 43.87±2.46 years, 20.78±1.03 kg m-2, respectively. Serum protein, albumin and bilirubin levels were significantly different in both male and female heavy and moderate drinkers. The activities of serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and gamma glutamyl transferase in the non-drinkers were significantly lower than in moderate or heavy drinkers of alcohol in both males and females. These findings indicate that alcohol consumption either as chronic or moderate, elevated the activities of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and gamma glutamyl transferase in both males and females, but more pronounced in the females. Serum protein, albumin and bilirubin levels were impaired by alcohol consumption in both males and females and may provide additional information in the diagnosis and management of alcoholism.