Double-blind study comparing efficacy and safety of alprazolam and bromazepam in 119 ambulatory anxious patients receiving flexible dosage. 119 ambulatory anxious patients (global score on the Hamilton anxiety rating scale between 18 and 35) have been included in this double-blind trial (duration 4 weeks) comparing alprazolam and bromazepam given at flexible dosage. The global score on the Hamilton anxiety rating scale improved by 57.8% and 55.3% for alprazolam and bromazepam respectively. The percentage of therapeutic success according to the psychiatrist and the patient were respectively 82.7% and 79.3% for alprazolam compared to 74.1% and 71.9% for bromazepam. Fewer side-effects were recorded in the alprazolam group (97) than in the bromazepam group (120) and global safety of alprazolam seemed superior (p = 0.07). At trial-end, mean dosage reached 1.70 mg/day for alprazolam and 10.35 mg for bromazepam, but no correlation was found between anxiety intensity and optimal daily dosage used; however, a correlation has been found between the improvement of the overall Hamilton rating scale score and the dosage given (p = 0.02). The overall results suggest that the efficacy/safety ratio is better for alprazolam.