Tomato has been listed as a host plant of the oriental tobacco budworm (OTB), Helicoverpa assulta for long time in literatures in our country, with which many reports from the field surveys disagreed. The present investigation aims to clarify if tomato plant is OTB host. Laboratory trials showed that OTB moth laid eggs on tomato plant, but neither detached tomato leaves nor potted plant supported neonate growth, and all the 3rd instar larvae feeding on the green fruits died before the 6th instar too. Death of the larvae could be attributed to presence of tomatine in these organs, and its contents reported in the literatures are in close to or exceed the LC₅₀ of 744 ppm for the neonates  as estimated using the artificial diet with different contents of the chemical. The field survey also excluded possibility of OTB infesting tomato plants. These results suggest that tomato plant is not OTB host and the records in the literatures might confuse H. armigera and H. assulta because of their similarity in morphology and feeding habits.