Treatment with pegylated interferon is usually used in active chronic hepatitis C in association with ribavirin. The adverse effects of interferon include influenza-like syndrome and mild respiratory manifestations, which are highly frequent. Among the immunomodulatory effects is the possibility of inducing or exacerbating autoimmune phenomena such as cutaneous or systemic sarcoidosis. We present a new case of pulmonary sarcoidosis induced by pegylated interferon in a 35 year-old woman with chronic hepatitis C who developed respiratory symptoms 4 months after starting therapy with pegylated interferon associated with ribavirin. Radiological images showed a micronodular pattern in both pulmonary fields together with hilar and mediastinal adenopathies. Transbronchial biopsy confirmed the presence of sarcoidal granulomas. After the diagnosis of pulmonary sarcoidosis, antiviral therapy was suspended with subsequent resolution of the clinical symptoms.