The current studies examined the relationship between the penchant to daydream about helping others and prosocial traits and behaviour. We reasoned that fantasising about prosocial acts should be positively associated with a more prosocial disposition and real behaviour. Across both studies, the findings suggest that people who exhibit prosocial characteristics (e.g., empathic concern, fantasy/fictional empathy, moral reasoning) are more likely to fantasise about prosocial behaviour, and these characteristics are reliably associated with increased helping behaviours. From Study 1, the correlational results showed that people higher in agreeableness exhibited a stronger tendency to engage in prosocial fantasising, and empathy, in part, mediated the relationship. The experimental results from Study 2 conceptually support those from Study 1; when prompted to fantasise about prosocial behaviour, those higher in agreeableness and openness to experience engaged in more helping behaviour, whereas in a control condition, no helping differences emerged. Finding that empathic concern was most consistently related to daydreaming is consistent with the theory in that people are more intrinsically motivated to promote other's welfare at a personal cost when they feel empathy. Engaging in prosocial fantasising may increase empathy, which in turn, may enhance one's prosocial disposition and increase one's helping behaviour.