Fungal endophthalmitis is a rare but severe clinical entity, occurring most commonly in patients with significant immunodeficiency, whereas infections caused by fungi of the genus Mucor spp. are exceptionally rare and aggressive. The occurrence of this type of infection in immunocompetent individuals has been reported only sporadically. This paper presents the case of a 76-year-old man without classic risk factors for opportunistic infections, who was admitted due to a gradual, progressive deterioration of vision in the right eye following an uneventful phacoemulsification cataract surgery. Based on positive cultures of material obtained from the anterior chamber, vitreous body, and a fragment of the lens capsule, fungal endophthalmitis caused by Mucor spp. was diagnosed. Intensive combined treatment was administered, including multiple vitrectomies along with local and systemic antifungal therapy, primarily with amphotericin B. Despite achieving control of the infection, severe anatomical complications, including choroidal and retinal detachment, could not be prevented, which led to permanent and significant visual impairment.