peer reviewed ; A retrospective study based on 4,307 drug patient records was designed to establish a chart of the consumption of benzodiazepines administered orally in a 635-bed teaching hospital, and to determine the influence of patient-related parameters (age, sex) and hospital-related parameters (type of services, prescription habits, etc.) on benzodiazepine Utilization. Another objective was to evaluate to which extent benzodiazepine consumption can be induced by hospitalization. A minor but statistically significant difference (p <0.05) was observed between the proportion of male (42.7%) and female (46.5%) users. Besides, when evaluating the consumption in number of defined daily doses per 100 beddays, there was little difference between the consumption of male (51.2 defined daily doses per 100 beddays) and female (52.8 defined daily doses per 100 beddays) patients. A significant influence of age was also observed with an increase of benzodiazepine use for patients aged from 15-20 to 40-45, followed by a progressive decrease for higher ages. With hypnotics, no peak of consumption related to age was observed but an increase of consumption from age 15-20 to 30-35. For higher ages the consumption of hypnotics was nearly stable or rising slowly. High variations in benzodiazepine utilization were recorded between hospital wards (median: 50.77 defined daily doses per 100 beddays, range 0.23-263.9). Finally, it was found that 6.8% of patients with a benzodiazepine treatment initiated during hospitalization may be considered as potential benzodiazepine consumers after discharge. © 1994 Royal Dutch Association for Advancement of Pharmacy.