CASE REPORT: A 30-year-old man was referred to our ocular oncology service with a diagnosis of amelanotic choroidal melanoma of the left eye. The following tests were performed: ophthalmoscopy, fluorescein angiography, indocyanine green angiography, ultrasonography, magnetic resonance imaging and biopsy. DISCUSSION: The diagnosis of giant nodular posterior scleritis, as suggested by ultrasonography, was confirmed by biopsy. A comprehensive medical evaluation was performed, but no etiology was found. The histology revealed a granuloma compatible with ocular sarcoidosis. A rapid response was obtained by systemic steroid administration (1 mg/kg). Sarcoidosis continues to be a challenge in diagnosis. It is important to distinguish nodular posterior scleritis from choroidal melanoma.