Altruism plays a role in mate choice, particularly in women’s preferences and in long-term (LT) relationships. The current study analyzed how these preferences interacted with another important mate choice variable, physical attractiveness. Here, female participants were presented with photographs of men of varying levels of physical attractiveness, alongside descriptions of them behaving either altruistically or not in different scenarios. The results showed women preferred altruistic men, particularly in LT relationships and that this interacted with physical attractiveness such that being both attractive and altruistic made a man more desirable than just the sum of the two desirable parts. Also, being altruistic made low attractive men more desirable but only for LT relationships. Finally, men who were just altruistic were rated more desirable than men who were just attractive, especially for LT relationships. Overall, these findings are discussed in terms of the role of altruism in mate choice, particularly in LT relationships and directions of future research.