A pilot audit of case records of consecutively discharged patients from a district general hospital was undertaken by specialist registrars, SHOs and senior nurses in order to identify adverse events (AEs) and critical incidents (CIs) related to hospital care. Experienced external assessors taught the clinical staff to use a previously validated structured method of case record review that facilitates analysis. The external assessors audited the same case records in parallel. Aggregated data from 154 case records of patients admitted to the general medical wards were collected for analysis. Fifteen AEs and 41 CIs were identified in the case records covering the hospital admission. In addition, 16 AEs and nine CIs were discovered to have occurred before admission or, for three AEs, shortly after discharge. One-half of the episodes related to problems arising during ward care and for one-half of these issues remained unresolved at the time of discharge. One-third of episodes related to medications or the administration of intravenous fluids--and in these cases there were defects in monitoring the patients' clinical progress. This study led to initiatives to improve care at the host hospital and we believe that further programmes along similar lines are indicated.