DISCUSSION: VLS is a rare condition defined as giant bullae occupying at least 1/3 hemithorax1. VLS should be differentiated from tension pneumothorax. CT is the imaging modality of choice. Bullectomy is done for symptomatic improvement but does not restore the collapsed lung in most cases.Smoking is the only known risk factor but marijuana use is emerging as a risk factor, especially, in concomitant smokers. Marijuana smoking involves a two-thirds larger puff volume, a one-third greater depth of inhalation, and four-times longer breath-holding time than tobacco smoking contributing to bullae formation2. CAP is the leading cause of ARDS with mortality of 30-50%. Theoretically, VLS can increase the morbidity and even mortality from pneumonia due to poor gas exchange and significant reduction in normal lung tissue.