The demographic, clinical and pharmacological risk factors for persistent tardive dyskinesia (TD) were investigated in a sample of 1745 patients. When simultaneously adjusting for the effects of demographic and pharmacological factors using multivariate logistic regression, female sex and advanced age were positively and significantly associated with increased risk of TD. Interaction between these two variables, investigated by cross-stratification, was significant. Furthermore, high neuroleptic dose and concomitant use of neuroleptic and antiparkinsonian drugs were both significantly associated with increased risk of TD. The results support the view that both vulnerability factors and high neuroleptic doses contribute to the occurrence of TD and further stress the relevance of a conservative use of antipsychotic medication, particularly in older women.