We report a patient with amyotrophic lateral sclerosis (ALS) who developed a pneumothorax after needle electromyography (EMG), probably of the intercostal muscles. Needle EMG on intercostal muscles has a high risk of pneumothorax, not only because electromyographers are unfamiliar to its technique, but also due to its close anatomical location to the pleural cavity. In our patient, advanced intercostal muscle atrophy due to disease process would have increased the risk further.
