We report two cases of pneumonitis caused by Seishinrenshiin. A 54-year-old woman and a 80-year-old man had taken Seishinrenshiin for cystitis and benign prostatic hypertrophy. Their chest radiograph showed diffuse ground-glass shadows in the whole lung fields and chest CT showed diffuse ground-glass-opacities predominantly in the lower lung fields of both lungs. Biochemical tests revealed mild liver dysfunction and inflammatory reactions. Their abnormal chest shadows disappeared after discontinuation of Seishinrenshiin. We should be aware that Seishinrenshiin, as well as other Chinese herbal medicine, could be cause of drug-induced pneumonitis.