The nuclear polyhedrosis virus of Spodoptera litura F. was formulated into wettable powders and dusts and their efficacy was tested against second instar larvae of S. litura in the laboratory. The results showed that wettable powder formulations were as effective as the unformulated virus. Wettable powder prepared with dedenol as the wetting and dispersing agent was better than dust formulations. When water was used instead of acetone in the preparation of the formulations particularly the dusts, the efficacy was increased. The WP formulation began to loose its virulence from the third month onwards of storage.