The merits and limitations of traditional and new markers for alcohol abuse (and abstinence) are critically examined for detection and monitoring of alcoholics, hazardous drinkers and binge drinkers. The traditional markers discussed include gamma-glutamyltransferase (GGT), aspartate and alanine aminotransaminases (AST, ALT) and mean corpuscular volume (MCV); new markers include mitochondrial AST, carbohydrate-deficient transferrin (CDT), serum/urine 5-hydroxytryptophol, beta-hexosaminidase and acetaldehyde adducts. The strengths and weaknesses of several of the self-reporting screening questionnaires are also explored. No laboratory test is reliable enough on its own to support a diagnosis of alcoholism. Sensitivities and specificities vary considerably and depend on the population concerned. GGT continues to remain the test that combines greatest convenience and sensitivity: its diagnostic accuracy can be enhanced by combination with other traditional markers (AST, ALT, MCV). None of the newer markers offers significant advantage, although CDT seems to be better at monitoring patients for increased alcohol consumption or progress towards abstinence.