Technical Abstract: Efficacy of using radio frequency (RF) 27.12 MHz was evaluated as a postharvest quarantine treatment against fifth instars of the codling moth, Cydia pomonella L. (Lepidoptera:Tortricidae), in apples, Malus sylvestris (L.) var. domestica (Borkn.) Mansf. Tests demonstrated that the energy fields between the RF unit's electrodes were neither predictable nor uniform. Moving fruits submerged in water during RF exposure may improve uniformity, but pulp temperatures varied considerably among fruits, among sites on the same fruits, and at different depths within the same site. As a result of these inconsistencies, quarantine efficacy was not obtained either using a range of final average temperatures from 40 to 68 degrees C (104.0 to 154.4 degrees F) or at holding times up to 20 minutes. We concluded it would be difficult to obtain the appropriate parameters for treatment efficacy and fruit quality maintenance using this technology under these conditions.