This paper examines the moral factors that motivate altruistic behavior on the part of Polish students toward Ukrainian war refugees within the context of economic theories on altruism. An online survey is used to itemise the students’ altruistic activities, explore what they see as their moral obligations, and elicit their views on supporting refugees. The data are analyzed in relation to Jonathan Haidt’s five moral foundations using correlation analysis and logistic models. The findings suggest that Haidt’s care/harm foundation significantly influences altruistic conduct towards refugees. The fairness/reciprocity foundation is negatively correlated with supporting refugees when such support is perceived as unfair. Expanding the circle of moral obligations (referred to as loyalty circles) is shown to have a positive and mostly significant effect on altruistic behavior. Moreover, the study shows that some Polish students acted contrary to their stated social preferences by supporting Ukrainian refugees despite believing that it is unfair. The paper concludes that these findings challenge the mainstream economic theories on altruism.