Recent observations suggest the existence of clonazepam abuse. In order to determine the importance of this practice and the characteristics of these consumers, a study has been carried out, based on data from the Provence-Alpes-Côte-d'Azur and Corsica health reimbursement system. Individuals from these regions affiliated to the French health reimbursement system, who have had a prescription of clonazepam reimbursed between January 1, 2001 and February 15, 2001, have been selected. The deliveries have been monitored over a 9 month-period. 9381 subjects have been selected. A sub-group of 1.5 per cent subjects with a deviant behaviour has been identified by factorial analysis and has been compared to the sub-group without deviant behaviour. The subjects with deviant behaviour are younger and mostly male. The dosage of clonazepam is higher (10.8 mg per day versus 2.1 mg per day) with a significantly higher proportion of benzodiazepine and high-dose buprenorphine. The number of deliveries is higher (19.4 versus 5.9) as well as the number of different physicians (4.5 versus 1.5) and pharmacies (5.9 versus 1.3). This study provides some arguments in favor of the potential of abuse and dependence of clonazepam and the necessity to reinforce its monitoring. This information requires to be relayed to health professionals.