Mortality data of navel orangeworm, Amyelois transitella, in response to nitric oxide fumigation treatments, are presented. This data set is associated with the study on responses of navel orangeworm (NOW), Amyelois transitella (Walker), to nitric oxide (NO) fumigation treatments. In the study, NO fumigation was evaluated for efficacy against eggs, larvae, and pupae of NOW. Larvae and pupae were fumigated both on artificial diet and in infested walnuts. Insects were fumigated with NO at different concentrations for different durations. Numbers of dead and alive insects at each life stages were collected for each treatment. NO fumigation was conducted under ultralow oxygen (ULO) conditions. So, each test included two controls: CK (in normal atmosphere) and ULO (under ultralow oxygen condition). Mortality rates from different treatments for each life stage were compared statistically to determine efficacy of NO fumigation.