A 38-year-old woman presented to the emergency department with a history of thoracic pain and anorexia for 1 week. Thoracic CT scan showed bilateral pleural effusion, a thoracentesis was performed revealing a transudate liquid with polymorphonuclears and predominance of eosinophils. After admission, the patient developed abdominal pain and the abdominal CT scan showed densification of the mesenteric fat characteristic of mesenteric panniculitis (MP). The patient went through investigation for secondary causes of panniculitis including infection, neoplasia and autoimmune diseases, and no abnormalities were found. The patient was treated with corticosteroids over a period of 3 months with complete resolution and without any signs of remission or secondary cause of MP. Moreover, the patient remained asymptomatic for 2 years after being discharged, which strengthens the diagnosis of MP that presented with eosinophilic pleural effusion.