Facing a protagonist's emotional mental state can trigger social emotions (or 'fortune of others' emotion), such as envy or gloating, which reflect one's assessment of the consequences of the other's fortune. Here we suggest that these social emotions are mediated by the mentalizing network. The present article explores the notion that the understanding of social competitive emotions is particularly impaired in patients with ventromedial (VM) prefrontal lesions. By manipulating a simple Theory of Mind (ToM) task, we tested the ability of patients with localized lesions to understand 'fortune of others' emotions: envy and gloating (schadenfreude). Patients were also assessed for their ability to recognize control physical and identification conditions. While envy is an example of a negative experience in the face of another's fortunes, gloat is thought to be a positive experience in the face of another's misfortune. Whereas in schadenfreude and envy the emotion of the self and the protagonist may be opposite, identification involves matching between the protagonist's and the observer's emotions. Patients with VM (N = 10) lesions (particularly in the right hemisphere), although showing intact performance on a basic first order ToM condition, and relatively preserved understanding of identification, did not recognize envy (F[6,76] = 3.491, P = 0.004) and gloating (F[6,76] = 3.738, P = 0.003). Impaired recognition of gloating involved additionally lesions in the inferior parietal lobule (P = 0.001). Furthermore, while patients with lesions in the left hemisphere were more impaired in recognizing gloating (a positive emotion), right hemisphere patients were more impaired in recognizing envy (a negative emotion), suggesting that the valence of these emotions may also be affected by the asymmetry of the lesion (F[6,68] = 2.002, P = 0.011). In addition, the ability to identify these emotions was related to perspective-taking abilities and ToM. We suggest that these results indicate that the mentalizing network including the VM has a fundamental role in mediating the understanding of competitive emotions such as envy and gloating.