PURPOSES: to identify the prevalence of the use of psychiatric drugs among patients admitted to medical and surgical clinics of a general hospital, and also the factors related to the consumption of this type of medication. METHOD: this is a transversal, descriptive, correlational study with quantitative analysis. For the collection of data, there was use of structured interviews and also reference to medical files. RESULTS: there was confirmation of a high prevalence of users of psychiatric drugs, which was associated to the female sex, to people who do not practice Roman Catholicism, and admittance to the clinic not covered by the Single Health System (Sistema Único de Saúde - SUS), as well as the presence of common mental disorders. Benzodiazepine drugs were the most commonly used psychiatric drugs. Among the total number of users, there has been the identification of patients who were not aware that they were receiving such medication. Doctors who are not psychiatrists were responsible for most prescriptions of psychiatric drugs. CONCLUSIONS: this signals the need to prepare health professionals to deal with psychological and social problems commonly found in clinical practice, in order to promote the rational use of psychiatric drugs.