The pistachio twig borer moth, Kermania pistaciella Amsel (Lepidoptera: Tineidae), is one of the primary pests of pistachio in Iran. This study was conducted during 2019 and 2020 at the Damghan Pistachio Research Station to evaluate the susceptibility of indigenous (‘Abbasali’, ‘Khanjari-e-Damghan’, and ‘Shahpasand’) and non-indigenous commercial (‘Owhadi’, ‘Akbari’, and ‘Ahmad-Aghaei’) cultivars. At the time of commercial harvest, 25 clusters were sampled from four sides of the canopy for each tree per cultivar. The percentages of pupal cocoon formation and adult emergence were obtained using the thermal requirement method. The percentage of infestation was determined based on the remaining clusters on the trees by longitudinally sectioning the rachis and peduncle to record active larval galleries and gum exudates. Based on the two-year combined analysis, differences in infestation levels among cultivars were statistically significant (P≤0.05). The highest and lowest infestation rates were recorded for Abbasali (9.3%) and Khanjari-e-Damghan (2.6%), respectively. The peak emergence of adult moths occurred on May 6th and May 3rd in 2019 and 2020, respectively. In the first year (2019), the 50% pollination date for ‘Ahmad-Aghaei’, ‘Owhadi’, ‘Shahpasand’, ‘Abbasali’, ‘Akbari’, and ‘Khanjari-e-Damghan’ was recorded as May 8, 11, 12, 12, 15, and 18, respectively. In the second year (2020), these dates were May 6, 8, 8, 9, 13, and 17, respectively. Early-flowering cultivars (e.g., ‘Ahmad-Aghaei’ with 50% pollination on May 6–8) were at the sensitive stage of fruit set and had soft rachis tissue during the pest’s peak emergence (May 13–16), whereas the late-flowering ‘Khanjari-e-Damghan’ cultivar escaped the critical period of primary damage due to delayed pollination (May 17–18). The information obtained from this study can be utilized in the management and control of the pistachio twig borer moth.