Pulmonary hypoplasia generally occurs in the neonatal period or in childhood and still exist until adulthood. Pulmonary hypoplasia is characterized by a decrease in the number of bronchial segments and decreased/absent alveolar air spaces. Diagnosis is usually made from history, spirometry, bodyplethysmograph, bronchoscopy, chest x-ray, contrast chest ct scan, chest ct angiography.Case Report: A 48 year old woman who had been in outpatient treatment for bloody streak cough was taken to referral hospital to establish the disease. In addition, she complaints with dry cough for a week and also accompanied with fever. The diagnose was established from cxr, thorax ct scan, bronchoscopy, thorax ct angiography. From chest x-ray showed a left-sided homogeneous opacity, further imaging chest computed tomography (ct) scan demonstrated a hypoplastic left lung with right lung hyperinflation, review thorax ct scan and the interpretation was left lung hypoplasia, 3D volume-rendered ct image depicts left lung hypoplasia, bronchoscopy from superior and inferior lobe revealed narrowed lumen, chest ct angiography was performed and supports the diagnose of left lung hypoplasia group 3 (Monaldi Classification). The patient had past history of similar respiratory symptoms 20 and 25 years ago and according to her, was treated on both occasions with pneumonia drugs based on chest X-ray findings. No old reports, papers, or investigations were available with the patient and she had remained almost asymptomatic till now. She was gave cefixime 200 twice daily for 5 days, paracetamol, tranexamic acid and vitamin.. Nowadays, she doesn't have respiratory symptoms Conclusion: Unilateral pulmonary hypoplasia is a rare disease. General treatment is conservative, although surgical resection is indicated in cases of severe cystic changes and severe symptoms