The seasonal influence on Haemonchus contortus infection in lambs and seasonal influence on response to treatment with albendazole was evaluated. Worm free lambs were artificially infected with 10,000 L3 of Haemonchus contortus in both seasons. Egg output was evaluated before and after treatment in the two seasons. There was no significant difference in the levels of haemonchosis in the lambs for both seasons. However there was a significant difference in egg output between the dry season and wet season after treatment with albendazole. The lower egg output in the dry season may not necessarily be as a result of response to albendazole treatment, other factor such as hyperbosis may have equally contributed. However, repeated deworming in the wet season has been recommended for effective control of haemonchosis.