The effect of the cause of a disaster, i.e. whether it was perceived to be caused by human or natural factors, on willingness to donate money to disaster victims was examined. In Study 1 (N = 76), the cause of a fictitious disaster was experimentally varied. In Study 2 (N = 219), participants were asked about their views regarding donations to two real-life disasters, one of which was perceived to be naturally caused while the other one was perceived to be caused by humans. In Study 3 (N = 115), the cause of a fictitious disaster was experimentally varied, but this time measures of the proposed psychological mediators of the effect on donations were included, namely perceived victim blame and the extent to which victims were thought to make an effort to help themselves. A measure of real donation behaviour was also added. In Study 4 (N = 196), the proposed psychological mediators were manipulated directly, and the effect of this on donations was monitored. Across all studies, more donations were elicited by naturally caused rather than humanly caused disasters. This difference was driven by a perception that the victims of natural disasters are to be blamed less for their plight, and that they make more of an effort to help themselves. Implications for theory and practice are discussed. Copyright © 2010 John Wiley & Sons, Ltd.