Following a rapid decompression in an altitude chamber for routine training purposes, a 38-year-old altitude chamber technician developed rapid onset of mental dullness, right arm weakness, and sensory deficits. Immediate treatment with compression therapy in a hyperbaric chamber resulted in complete resolution. Ambient pressure changes great enough to result in arterial air embolism due to an explosive or rapid decompression have been described as a potential hazard in aviation, although no actual cases of such a phenomenon have been previously reported. The aeromedical considerations of this complication are discussed.