Alcoholic beverages, and the problems they engender, have been familiar in human societies since the beginning of recorded history. Among a variety of blood tests used to aid the diagnosis of alcohol consumption and related disorders, laboratory tests are particularly useful in settings where cooperativeness is suspected or when a history is not available. Biochemical and haematological tests, such as gamma-glutamyltransferase activity, aspartate aminotransferase activity and erythrocyte mean corpuscular volume, are established markers of alcohol intake. Carbohydrate-deficient transferrin is the only test approved by the FDA for the identification of heavy alcohol use. Total serum sialic acid and sialic acid index of Apolipoprotein J have the potential to be included in a combination of measurements providing an accurate, more exact, assessment of alcohol consumption in a variety of clinical and research settings. Several other markers with considerable potential for measuring recent alcohol intake include beta-hexosaminidase, acetaldehyde adducts and the urinary ratio of serotonin metabolites, 5-hydroxytryptophol and 5-hydroxyindoleacetic acid. These markers provide hope for more sensitive and specific aids to diagnosis and improved monitoring of alcohol intake.