This study describes the extent of inappropriate day-hospital assistance and the effect of different variables on such inappropriateness. A random sample of patients admitted to pediatric and adult day-hospital care during the period Janurary--December 2000 in three hospitals located in the area of Catanzaro, Italy were reviewed. Assessment of appropriateness was made for the first access and for each of the following accesses in day-hospital. A total of 826 patients were reviewed. Overall, 23.8% of the first access in day-hospital care was judged to be inappropriate and 49.7% of the sample showed at least one inappropriate access for day-hospital care with a mean of 1.4 inappropriate accesses. Multiple logistic regression analysis indicated that the inappropriateness of the first access significantly increased with relation to lower distance from hospital to patient's home; admission to general medicine wards; first access from Monday to Thursday; lower number of patient's diagnostic procedures and medical examinations in the first access. Stepwise multiple linear regression analysis showed that the number of inappropriate accesses was significantly higher for general medicine and surgery and trauma/orthopedics wards; in patients who the first access was inappropriate; in those who received a lower number of diagnostic procedures and medical examinations; in patients who showed a higher length of care in day-hospital. The findings suggest the need for standardized diagnostic and therapeutic guidelines for day-hospital care.