Chronic granulomatous inflammation may develop after injecting foreign oily substances into the penis. The disorder affects mainly the site of administration, but regional lymphadenopathy or even systemic disease can occur. We present a 39-year-old man with petroleum jelly-induced penile lesion and unilateral inguinal lymphadenitis mimicking incarcerated inguinal hernia. At hernioplasty no hernial sac was found, but enlarged lymph nodes suspicious for malignancy were identified. The histopathologic findings of these nodes were consistent with mineral oil granuloma. Paraffinoma of the male genitalia can cause various clinical features posing a differential diagnostic dilemma. Regional lymphadenitis may be the main clinical characteristic. Patient's history, physical and histopathological examination are required to establish the diagnosis.