A young man was found dead at the scene of a residential fire, although three persons who had been in the same room escaped. Autopsy disclosed soot in the trachea, the bronchi, and the alveoli. Forensic toxicological analyses were performed using the intratracheal gas, left and right ventricular blood, urine, stomach contents, cerebrum, cerebellum, left and right lungs, liver, spleen, kidney, skeletal muscle, and adipose tissue. Ethanol and toluene were qualitatively detected in the intratracheal gas by gas chromatography-mass spectrometry. Ethanol concentrations were not at the toxic level, while toluene concentrations in the blood and cerebrum were almost at the lethal level. However, since the preservation of the capacity for vital reactions was apparent at the autopsy in the form of soot in the air passages and the formation of CO-Hb in the blood, it was surmised that the victim was still alive when the fire broke out, but subject to severe disturbance of the central nervous system function. The cause of death was diagnosed as death due to fire after thinner abuse. Figure, table, references