Three experiments were conducted to further examine how prospection (i.e., thinking about the future) fosters prosociality. In Study 1 (n = 238), participants who wrote about the future expressed significantly stronger prosocial intentions than people who wrote about the past. In a similar study (n = 87), participants who wrote about the future were significantly more likely to behave prosocially than those who wrote about the past. In Study 3 (n = 203), mediational analyses revealed that prospection and optimism each predicted positive affect, which then predicted stronger prosocial intentions. These findings extend previous work by demonstrating that prospection enhances general prosocial intentions, that this effect extends to prosocial behavior, and that the effect is partially mediated by positive affect.