International health sciences students face demanding clinical training alongside cultural adjustment pressures, yet their responses vary considerably. Gender and academic level are theoretically grounded candidates for explaining this variation, drawing on tend-and-befriend theory and Conservation of Resources theory respectively, but their moderating role in the acculturation–resilience relationship remains underexamined, particularly outside Western settings. This study examined whether gender and academic level moderate the relationship between acculturation orientations (heritage and mainstream) and academic resilience among international health sciences students. This cross-sectional secondary analysis included 316 international students at Tehran University of Medical Sciences. Acculturation was assessed using the Vancouver Index of Acculturation and resilience using the Academic Resilience Scale. Hierarchical multiple regression tested control variables, acculturation orientations, and four interaction terms (Heritage × Gender, Mainstream × Gender, Heritage × Academic Level, Mainstream × Academic Level). Bootstrap resampling (5,000 replications) confirmed robust interactions. Both heritage orientation and mainstream orientation were strongly and positively associated with academic resilience. The interaction terms added a small but significant increment in explained variance (ΔR² = 0.024, p = 0.018). Academic level significantly moderated both relationships, with stronger associations among postgraduate than undergraduate students, and these effects held under bootstrap resampling. Gender did not significantly moderate either relationship. Inconclusion, academic level, rather than gender, shapes how acculturation relates to academic resilience among international health sciences students in this non-Western setting. Universities supporting this population may benefit more from resilience programming structured around academic level than from approaches differentiated by gender.