Marijuana is one of the most extensively smoking substance all around the world, although not common in our society. Its effects on lung are similar to tobacco, causing increased cough, sputum, hyperinflation, and rapid bronchodilatation following with possible airway obstruction. Chronic usage of marijuana may cause a variety of conditions such as bronchitis, large bullae formation, and pneumonia. Here, we report an uncommon case of hidden marijuana smoking causing acute inhalation injury. A 39-year-old male had consulted clinics with sudden onset of dyspnea, cough, and nausea. His chest X-ray and thorax computed tomography have revealed peripheral opacities with ground-glass infiltrations. After a detailed review of history, he was diagnosed with acute inhalation injury due to hidden marijuana smoking. As a conclusion, clinicians who encounter with individuals who have concurrent inhalation damage need to take a careful exposure history and should be alert for the possibilities of further complications and a worsening clinical picture.