A 65-year-old man had undergone uneventful extracapsular cataract extraction in the left eye and developed posterior capsule opacification. This opacification was successfully treated with a Nd:YAG laser capsulotomy 4 months after the cataract surgery. However, 1 month later, he began reporting of decreased vision in his left eye. On examination, his visual acuity was correctable to 20/30, and he was noted to have a white infiltrate in the anterior vitreous. No anterior chamber inflammation was found. The patient was referred to a retina specialist who began treatment with topical steroids for presumed persistent postoperative inflammation. Although intraocular lymphoma was considered, it was felt to be less likely. After the patient's condition did not improve after being treated with topical steroids, he was taken to the operating room for a vitreous biopsy and intravitreal antibiotics because of a concern for chronic postoperative endophthalmitis. Vitreous cytology and cultures were performed, and intravitreal injections of vancomycin (dose, 1 mg) and ceftazidime (dose, 2.25 mg) were given, with uneventful results. Prior to the intravitreal injection of amphotericin B, it was noted that the syringe was “too yellow.” The pharmacist was contacted, and the dilution was confirmed. Because the surgeon did not feel comfortable with the color of the medication, he only injected 40% of the initially intended dose. The following morning, the patient had severe ocular pain in the left eye, and there was marked intraocular inflammation. It was then discovered that the requested dosage was 400 μg/0.1 mL of amphotericin B, instead of 4 μg/0.1 mL. By injecting 40% of the intended dose, the patient received 160 μg of amphotericin B. The patient was immediately taken back to the operating room that morning for a washout of the intravitreal antibiotics. He received periocular and intravitreal injections of steroids and was monitored closely in the hospital for the next 3 days. Six days after surgery, his visual acuity had improved from light perception to 20/200. A fundoscopic examination at that time revealed vitreous debris and fibrin but no retinal detachment. The patient's visual acuity continued to improve slowly, and 2 years later, his vision was correctable to 20/30. The patient had concentrically constricted visual fields on Goldman perimetry, which was later considered to be nonphysiologic on tangent screen testing. An electroretinogram showed normal B-wave amplitudes with delayed implicit times.