EN
Spontaneous pneumothorax is most common in adolescents and young adults. Some of them develop contralateral pneumothorax. In this paper, we report the case of a patient with spontaneous contralateral pneumothorax, whose body mass index (BMI) was 18.8 kg/m2. For either chest physicians or thoracic surgeons, follow up with recognition of increased risk of the contralateral pneumothorax is important especially in patients with contralateral bullous lesions and low BMI.