Prescribing patterns of neuroleptic drugs in a population of about 3,700,000 inhabitants were analysed using all individual prescriptions delivered by the Italian National Health Service during 4 years (1986-1989). Data contained in a regional prescription database were analysed using an outpatient drug monitoring system (VIDEOFAR). The proportion of subjects receiving neuroleptics was about 1.3% of the entire population. During 1989, 20.2% of 52,716 observed subjects received multiple neuroleptic therapy. Haloperidol, the most frequently prescribed antipsychotic, was dispensed to 21.3% of the individuals as the only neuroleptic treatment. Consumption sharply increased with age and about 60% of patients receiving a prescription were women. Nonetheless, among the heavy users in the younger ages, the male-to-female ratio is significantly greater than one. Although the principal indications for neuroleptics are subacute or chronic clinical conditions, a surprisingly high proportion of subjects (ranging from 48% to 76% depending on the type of neuroleptic) received only one single prescription during 1989.