We report here the first use in Tourette's syndrome of the nonsteroidal androgen receptor blocking agent flutamide. One man and one woman underwent open trials of the medication, and a second man participated in a placebo-controlled, double-blind crossover trial. Improvement in tic symptoms ranged from 45 to 60%. The improvement was sustained in the woman during daily flutamide use and in one man during its intermittent use. One man's symptoms became refractory to treatment after 5 weeks of flutamide use, whereas the woman became depressed and had protracted diarrhea during her treatment.