Pleural effusion is a common clinical problem which differentiated into transudates and exudates according to Light’s criteria, based on the protein and lactate dehydrogenase levels in pleural fluid and serum.The angiopoietins are protein growth factors that promote angiogenesis.There are now four identified angiopoietins: Ang1, Ang2, Ang3 and Ang4.Ang-2 levels are elevated in exudative PEs, and they correlate with levels of PF VEGF levels and markers of pleural inflammation.