Relying on a quasi-experimental setting and a sample of Italian households, we study the role of time preferences on donation choices. Specifically, we apply the generalized propensity score methodology finding that both the amount and the probability of donating (i.e., altruism) vary non-monotonically with impatience in intertemporal choice, declining at higher levels of impatience. We then provide a theoretical model whose predictions are consistent, under fairly general conditions, with these empirical findings. Consistent with previous experimental evidence, these results support the view that psychological discounting matters for altruistic behaviour.