Benzodiazepine overdose is the most common of admission to the Toxicological Unit of the University of Florence. The aim of this study has been to evaluate the efficiency of Ro 15-1788 in benzodiazepine and mixed drug overdoses. The administration of Ro 15-1788 was followed by a quick reversal of central nervous system depression and was more effective in benzodiazepine overdoses than in mixed drug overdoses. The dose was titrated individually and the range 2-10 mg was effective according to the conditions of the patient. In some cases, the comatose state relapsed; further administration of Ro 15-1788 again promptly reversed the condition. On awakening, two patients displayed anxiety and restlessness.