The patient was an 84-year-old woman who took a combination cold remedy, Shin-Rulu-A' for three days because of fever and cough. However, her symptoms worsened and she visited our hospital. Arterial blood gas analysis revealed severe hypoxemia and chest computed tomography showed diffuse ground glass opacities in both lungs. Analysis of bronchoalveolar lavage fluid disclosed an increased proportion of lymphocytes. The cold remedy was stopped, corticosteroids were administered, and she recovered. After positive results of lymphocyte stimulation testing to Shin-Rulu-A, a diagnosis of drug-induced pneumonitis was made. However the responsible ingredient was not established, because lymphocyte stimulation tests for each ingredient in Shin-Rulu-A were negative. To the best of our knowledge, this is the second report of Shin-Rulu-A-induced pneumonitis in Japan.