1,2-Dichloropropane (1,2-DCP) is used widely in Korea as a substitute for trichloroethylene or methylene chloride. Some companies mistakenly consider that 1,2-DCP is an eco-friendly detergent because its use is not regulated, but 1,2-DCP is known to inhibit the central nervous system in animals; a few cases of accidental exposure have been reported in humans. We present a case of acute encephalopathy caused by exposure to 1,2-DCP. A 41 yr-old male presented with dizziness, headache, and diplopia after exposure to the detergent without protective equipment. Brain magnetic resonance imaging suggested metabolic encephalopathy, but the patient had no thiamine deficiency and no other metabolic disorder. As the symptoms had commenced after exposure to a large amount of solvent while skimming rust from the surface, and as the symptoms were more severe during the work week, improved on weekends, and disappeared after solvent exposure ceased, the toxic encephalopathy was likely induced by inhalation of the detergent.