A 42 year old female came with the chief complaints of shortness of breath,left sided chest pain and fever since 2 months and had similar complaints since 4 years, aggravated since 2 months and was diagnosed in the past as pleural TB by doing pleural fluid aspiration cytology 2 years back and she had taken ATT for 9 months.She was investigated with chest X ray PA view and CECT chest – non homogenous opacification of left hemithorax with multiple small circular shaped cysts with collapse of left lung and mediastinal shift to right side with probable diagnosis of hydatid cyst in left hemithorax. On ultrasound abdomen,no cysts were found in the liver,spleen. Surgical treatment was planned as excision of mass/cyst under general anaesthesia.Patient was kept on oral albendazole 400mg twice daily for 6 months and regularly followed up.Thepericyst, daughter cysts were sent for histopathological examination and diagnosis was confirmed.