People tend to assume that outcomes are caused by dispositional factors, for example, a person's constitution or personality, even when the actual cause is due to situational factors, for example, luck or coincidence. This is known as the “correspondence bias.” This tendency can lead normal, intelligent persons to make suboptimal decisions. Here, we used a neuropsychological approach to investigate the neural basis of the correspondence bias, by studying economic decision-making in patients with damage to the ventromedial pFC (vmPFC). Given the role of the vmPFC in social cognition, we predicted that vmPFC is necessary for the normal correspondence bias. In our experiment, consistent with expectations, healthy (n = 46) and brain-damaged (n = 30) comparison participants displayed the correspondence bias during economic decision-making and invested no differently when given dispositional or situational information. By contrast, vmPFC patients (n = 17) displayed a lack of correspondence bias and invested more when given dispositional than situational information. The results support the conclusion that vmPFC is critical for normal social inference and the correspondence bias. The findings help clarify the important (and sometimes disadvantageous) role of social inference in economic decision-making.