The cross-cultural validity of the Alcohol Dependence Syndrome was tested on 13 symptoms of alcohol dependence which were assessed as part of a WHO collaborative study of the early detection of harmful drinking. The subjects were drinking patients in health care settings in Australia, Bulgaria, Kenya, Mexico, Norway, and the US. Principal Components Analyses were performed on the symptoms in each centre, and the degree of agreement between the results was assessed by calculating coefficients of congruence between the item loadings on the first principal component. In all six centres the first Principal Component accounted for at least half of the total variance and all symptoms had positive loadings greater than 0.40 on the first Principal Component. The coefficients of congruence were all 0.98 or more, and the 13 symptoms had internal consistency coefficients of 0.94 or more. An alcohol dependence score defined by the sum of positive responses to the 13 alcohol dependence symptoms was positively correlated with self-reported alcohol consumption, alcohol-related problems, serum gamma glutamyltransferase and a clinical examination assessment of alcoholism in all six samples.