Increasing research shows pubertal development accelerates following threats while it decelerates following deprivation. Yet, these environmental stressors are unlikely to occur in isolation. We investigated how war exposure and energetic stress impact pubertal development using data from the longitudinal Biological Pathways of Risk and Resilience in Syrian Refugee Children study. Our sample included 1,600 male and female Syrian refugee children and their caregivers who lived in temporary settlements in Lebanon. We hypothesized that (a) energetic stress suppresses pubertal development; (b) war exposure accelerates pubertal timing in boys and increases risk of menarche in girls, but only when energetic stress is low; and (c) when energetic stress is elevated, effects of war exposure on pubertal development will be attenuated. Among boys, we did not find support for Hypothesis 1, but Hypotheses 2 and 3 were supported. Exposure to morbidity/mortality threats accelerated pubertal timing; this effect was attenuated under conditions of elevated energetic stress. Among girls, we found support for Hypothesis 1, but not for Hypotheses 2 and 3. Elevated energetic stress decreased the risk of menarche in girls. Neither war exposure, nor any interactions with energetic stress, predicted risk of menarche. Sensitivity analyses revealed a significant interaction between bombing exposure and the amount of time since leaving Syria. Bombing decreased the risk of menarche, but only for girls who had left Syria four or more years prior to data collection. We discuss implications for translational efforts advocating for puberty screening in medical and mental health settings to identify trauma-exposed youth.