A 55 year old male came with the chief complaints of shortness of breath,chestpain and cough since 6 months and had similar complaints 6 months back,diagnosed as right pleural effusion and ICD insertion was done. As symptoms are not relieved he was again investigated 4 months later and found to have left pleural effusion and ICD insertion was done. He had taken ATT for 9 months.He also underwent thorocoscopy.Then he underwent HRCT CHEST found to have ?loculated hydro pneumothorax with mediastinal cyst. Surgical treatment was planned as excision of cyst /mass and loculated hydro pneumothorax under general anaesthesia. Intra operative findings were Huge dumb–bell shaped cyst of 15*20cms abutting anterior pericardium and Cyst was extending into mediastinal pleura and both sides of chest. Post operatively patient was stable and regularly followed up. mediastinal cyst were sent for histopathological examination and diagnosis was confirmed as brochiogenic cyst.