Sclerosing mesenteritis (SM) is a rare, idiopathic disorder of unknown aetiology that involves the adipose tissue of the mesentery, being characterized by chronic and non-specific fibrous inflammation. Patients usually present with non-specific clinical manifestations, such as abdominal pain and diarrhoea. The diagnosis of SM is difficult and it can be definitely established only by means of surgical or imaging-guided biopsy. Different therapeutic strategies have been used in case series with different rate of success. The disease is generally self-limiting, and the long-term prognosis is good, even if some cases of severe SM are reported in literature. Here, we report a fatal case of sclerosing mesenteritis associated to protein-losing enteropathy.