Decomposition of NO2 in N-2 by 193-nm ArF excimer laser was studied at atmospheric pressure. The NO, conversion was 86% and the formation ratios of N-2, O-2, and NO were 32, 75, and 22%, respectively, at a low NO, concentration of 200ppm. The lower NO yield than that predicted from simple NO2 -> NO + O photolysis was explained as the second absorption of 193-nm light by NO (X-2 Pi: nu" > 0) followed by N + O predissociation and subsequent secondary reactions leading to N-2 and O-2.