Introduction: Primary spontaneous pneumothorax is relatively uncommon in children and adolescents and typically occurs in otherwise healthy individuals. It is most commonly attributed to rupture of apical subpleural blebs, leading to air leakage into the pleural space. Case: A 13-year-old previously healthy boy presened with a two-week history of cough, chest pain and exertional dyspnea for 3 days. There was no significant past medical history . His BMI was 13.6kgm-2. Increased arm span-to-height ratio (1.03). Reduced upper-to-lower segment ratio (0.8). He had arachnodactyly , with positive wrist and thumb signs. Beighton score was 4. On examination, respiratory rate was 24 /min, with diminished chest expansion, reduced air entry , decreased vocal fremitus and vocal resonance on left side. His saturation was 99% on air. Other systemic examination were unremarkable. Based on the Revised Ghent Criteria, the systemic score was 6. Full blood count was normal, with elevated inflammatory markers. Chest X-ray demonstrated a left-sided pneumothorax. HRCT of the chest revealed hydropneumothorax with focal area of subpleural blebs in apex of left lung and multiple areas of atelectasis in left lung extending up to the pleural surface, without broncho pleural fistula. Echocardiography , ophthalmological examination and Gene Xpert were normal. A Left sided intercostal drainage tube was inserted and the pneumothorax resolved. Subsequently , he underwent left-sided video- assisted thoracoscopic pleurectomy and bullectomy . He remains under further evaluation. Conclusions: Connective tissue abnormalities predispose to spontaneous pneumothorax due to structural lung weakness and require multidisciplinary follow-up and long-term surveillance,as systemic features may develop over time.