Flunarizine markedly depressed vestibular activity in rabbits. The vestibular effect was also evaluated in a double-blind multiple cross-over study in human volunteers, using cinnarizine as a reference drug. Dosage was 10 and 30 mg of e and 15 and 45 mg of Flunarizine cinnarizine. Electronystagmographic tracings were taken at different time intervals after drug intake. There was a good correlation between nystagmus duration and peak velocity of the slow nystagmus phase. At 2.5 h, both doses of flunarizine were more active than cinnarizine 15 mg. When the results of all cinnarizine tests were compared with those of flunarizine, there was a significant difference in favour of flunarizine.