To date, several biological alterations associated with the refugee status have been investigated. However, none of them has focused on the allostatic load (AL) index that is a collective measure of biological responses to stress. Therefore, the present study aimed to assess the AL index and its correlates in 60 Ukrainian refugees who migrated to Poland after the Russian invasion. The AL index was measured in 60 Ukrainian refugees and 50 controls matched for age and sex. It was based on sex-specific distributions of 15 biomarkers (cardiovascular markers, anthropometric measures, inflammatory markers, glucose homeostasis parameters, lipids, and steroids). Psychopathological symptoms and behavioral characteristics were assessed using self-reports. Refugees had significantly higher AL index together with higher scores of insomnia, negative affect, depressive and anxiety symptoms, avoidance and hyperarousal symptoms of post-traumatic stress disorder as well as lower levels of positive affect. Similarly, a lifetime exposure to traumatic stressors was significantly higher among Ukrainian refugees. Linear regression analyses demonstrated that lower levels of positive affect (interactive effects with the refugee status but not main associations) and higher levels of insomnia (interactive effects with the refugee status and main associations) were associated with elevated AL index after adjustment for age, education, cigarette smoking status, somatic disease, medication use, and head trauma history. In summary, the findings indicate systemic dysregulations of biological stress responses in Ukrainian refugees that are attributable to higher levels of insomnia and lower levels of positive affect in this population.