Azodicarbonamide is a low molecular weight foaming agent for plastics and rubbers. Azodicarbonamide can elicit acute and chronic health related problems due to its potential for pulmonary and cutaneous sensitization. Some cases of occupational asthma associated with exposure to azodicarbonamide have been reported, of which only a few cases were confirmed by specific inhalation challenges. Here, the first case of occupational asthma due to azodicarbonamide in Korea, in which the diagnosis was confirmed by specific inhalation challenge, is reported.