Relying on the framework provided by Schwartz's theory of personal values, we investigated whether values can help explain prosocial behaviour. We first distinguished value-expressive behaviours from value-ambivalent behaviours. The former are compatible with primarily one value or with congruent values, the latter with mutually conflicting values. In Study 1, an analysis over all 41 (39 unpublished) samples in which we measured personal values and prosocial behaviour in monetarily incentivized strategic interactions (N = 1289; data collected between 2007 and 2010 in China, Finland, Germany, Israel, and the West Bank) supported our idea that personal values, universalism in particular, predict value-expressive (prisoner's dilemma cooperation and trust game back-transfers) but not value-ambivalent behaviours (trust game transfers and ultimatum game proposals and responses). Study 2 (N = 56) focused on dictator game behaviours, which we expected and found to be strongly value-expressive. The findings contribute to the ongoing discussion on whether and under which circumstances values shape behaviour. Copyright © 2013 John Wiley & Sons, Ltd.