Objective - assessment of the burden perceived by a sample of key-relatives of schizophrenic patients. Design - Observational study of key-relatives of patients with a PSE-CATEGO diagnosis of active paranoid schizophrenia. Assessment of possible correlations between the family burden, the patients' symptoms and disabilities, as well as the relatives attitude of overinvolvement and criticism. Setting - Inpatient and outpatient psychiatric units of the Department of Psychiatry of the First Medical School, University of Naples. Subjects - 25 patients, with a diagnosis of active paranoid schizophrenia, according to ICD-9 diagnostic criteria, minimun illness history 1 year, at least one previous admission, living with at least one adult relative. Main outcome measures - Standardized assessment of patients clinical status and social disability and of relatives clinical status attitude and perceived burden. Results - The burden, both objective and subjective, was found to be present to a marked or very marked degree in more than 50% of the inteviewed relatives. A marked effect of the patients illness was observed especially on relatives social contacts and leisure activities. Also the attitudes of criticism and overinvolvement were detected in the great majority of the relatives. 52% of the relatives, when assessed by the PSE-9, received a psychiatric diagnosis. The objective burden was found to be associated with some «negative» symptoms and deficits of social functioning in the patients. Finally, significant correlations were observed between the objective and subjective dimensions of the burden and the relatives attitudes of hypercriticism toward the patients. Conclusions - The present study seems to be relevant both from the epidemiological point of view and for psychiatric care planning.