Protothecosis is an unusual human infection, caused by the genus prototheca, especially Prototheca wickerhamii. A 80-year-old immunocompetent man presented with a 1-month history of multiple reddish brown lobulated plaques on the scalp and face. He denied any history of trauma and had no evidence of underlying diseases such as diabetes mellitus or malignancy. On histopathological examination, characteristic morula-like sporangia in the dermis was revealed. After treatment with oral itraconazole for 8 weeks, the patient's skin lesions are almost healed.