A 38-year-old Iraqi female, presented with one-year history of exertional dyspnea and exercise intolerance, without systemic or constitutional symptoms. Clinical examination revealed bilateral basal crackles with signs suggestive of left side pleural effusion, chest x-ray showed left sided pleural effusion, and diffuse bilateral basal pulmonary shadowing. Her biochemical analysis, hematological tests, electrocardiogram and echocardiography were normal, aspiration of the fluid revealed a chylothorax, the radiological shadowing was proved by computed tomography scan of the chest to be diffuse cystic lesions involving mostly the lower lobes. Open lung biopsy showed dilated lymphatic vessels with surrounding inflammatory cells and smooth muscle fibers consistently with the diagnosis of pulmonary lymphangioleiomyomatosis LAM.