This study examines the properties of the Child and Adolescent Psychiatric Screening Inventory-Retrospect, CAPSI-R, a self-report 146-item questionnaire for adults concerning earlier child psychiatric symptoms, comprising both DSM-IV categories and functional impairment. The instrument was mailed to 359 former child psychiatric patients born between 1951 and 1977 (164 of whom responded) and to a matched control group (193 of whom responded). There was good internal consistency (Cronbach's alpha ranged between 0.62-0.93, and between 0.76-0.93 after elimination of one item). The lifetime prevalence of a mental disorder was 87.8% in the former patients' without considering impairment and 76.8% when impairment was considered. The corresponding figures for the control group were 49.7% and 10.4%, respectively. When the former patients' CAPSI-R diagnoses (with incorporation of the impairment criterion) were validated against the DSM-IV diagnoses based on information in their medical records, generally, an acceptable sensitivity and specificity were obtained. The overall kappa between CAPSI-R diagnoses and those from medical records was 0.79. The CAPSI-R shows promise for further evaluation and may be useful in recognising child and adolescent mental disorders in adults.