To assess the appropriateness of hospitalisation days, a cross-section study was conducted in a French university hospital. Concerning both medical and surgical wards, three days were randomly chosen from April to June 2001. A total of 2,180 hospitalisation days were evaluated in accordance with the French appropriateness evaluation protocol (AEPf) with 10.9 per cent in medicine and 7 per cent in surgery judged as inappropriate. The delay tool was used to identify the causes of inappropriate days. The first cause of delay (68 per cent) was the unavailability of outside care (UOC), respectively 83.2 per cent and 61.4 per cent in surgical and medical services. The UOC was more pronounced for patients living in Caen (34 per cent) which represented only 20 per cent of hospitalised patients in the university hospital of their city. These results allow for suggestions for services to improve organisation and bring arguments for better health care.