Abstract: A field experiment during Kharif 2003 and 2004 to evaluate the efficacy of six insecticides at farmers field against Helicoverpa armigera infesting tomato. Among the treatments imidacloprid at 0.03% proved more effective followed by deltamethrin and fluvalinate. The spraying of these insecticides on tomato resulted in significantly higher reduction of larval population. The field data showed that imidacloprid gave a significantly higher increase in yield (>78%) over control followed by deltamethrin. Imidacloprid (0.03%) avoided 46% yield loss on tomato crop.