40 parasitologically confirmed cases of kala azar, were randomly allocated into four treatment groups to assess the effect of verapamil on fresh and antimony resistant cases of kala azar. Untreated patients received sodium stibogluconate only or in combination with oral verapamil. Antimony-resistant patients were treated with sodium stibogluconate combined with oral verapamil or pentamidine. The patients were followed up for six months. Verapamil neither shortened the duration of treatment nor increased parasitological cure rate nor improved the ultimate cure. In antimony unresponsive patients it did not reverse unresponsiveness.