Diterpenoid and norditerpenoid alkaloids were tested against Tribolium casteneum (Herbst.) in order to assess their repellent activity. Of 29 tested alkaloids, 21 compounds showed promising insect repellent activity, while eight of them were not found to be active. The alkaloids were obtained from Delphinium, Consolida and Aconitum species. The highest activity was found in hetisine, a diterpene alkaloid (59.37%) and the lowest activity in another diterpene alkaloid venulol (31.25%).