Nattrassia mangiferae is a plant pathogen that is also known as a cause of skin infection in humans. Reports of invasive human infection are extremely rare. A 60-year-old-immunocompetent patient presented with endophthalmitis one week after the left eye was injured by a piece of grass. Cultures of an aqueous tap grew N. mangiferae. The patient responded to oral ketoconazole. This suggests that N. mangiferae may be an invasive pathogen in plant penetration injuries and that ketoconazole may be an alternative treatment, especially in countries with poor resources.