A 64-year-old woman with hepatitis C was treated using combination therapy with peginterferon α-2a and ribavirin. After 3 months, she presented with raised nodules on her knees and elbows. After 8 months, she developed painful subcutaneous nodules on her forearms. We diagnosed sarcoidosis with both plaques and subcutaneous nodules associated with combination therapy with peginterferon α-2a and ribavirin. Sarcoidosis with both plaques and subcutaneous nodules is very rare. The patient had a sustained Th2 response in the liver. And a sustained Th1 response occurred only in the skin. It is likely that, for this reason, sarcoidosis was localized to the skin, and the patient developed sarcoidosis with both plaques and subcutaneous nodules.