Introduction: Mesenteric panniculitis is a rare disorder characterized by chronic, non-specific inflammation involving the adipose tissue of the bowel mesentery of unknown aetiology. It has been associated with different processes, including digestive and urothelial malignancies. Case report: A 44-years-old man carne to the Emergency Department complaining of mesogastric pain for the last 24 hours. CT sean showed an increased density of the mesenteric adipoid tissue. Mesenteric paniculitis was diagnosed and antibiotic treatment was instaured. The patient recovered uneventfully. Two months later the patient was diagnosed of an infiltrating urothelial carcinoma. Conclusions: Mesenteric panniculitis may be associated with malignancies and other pathologies. It is advisable to perform tests to dismiss the coexistence of these disorders. In those cases, in which associated diseases could not be demonstrated, a frequent follow-up would be advisable to achieve an early diagnosis if these appear.