The aim of this study was to determine the most salient predictors of tolerance to human diversity. A total of 118 individuals (M = 32.93 years, standard deviation = 13.80) responded to dilemma-like stories involving holding prejudicial beliefs (beliefs), talking about them (speech) and acting on them (acts). Participants also completed the openness and agreeableness scales from the Big Five Inventory and the Interpersonal Reactivity Index. Differences in tolerance judgements were found to be related to differences in personality characteristics. Results showed that openness and agreeableness were predictors of tolerance in the belief dimension, whereas the most salient predictor of tolerance in the speech and act dimensions was empathic concern, which also mediated the relationships between agreeableness and tolerance for these dimensions. These findings are not unexpected because holding intolerant beliefs is inconsistent with having an open mind, and intolerant speech and actions are inconsistent with pro-social behaviour, of which tolerance is arguably one form.