There are few reports in the literature of fat embolism syndrome after cementless total hip arthroplasty (THA). Most reported cases have occurred after fracture or cemented THA. We report a case of a healthy 51-year-old woman who underwent THA for osteoarthritis under spinal anesthesia. A press-fit cup and extensively porous-coated diaphyseal locking stem were used and inserted without cement. In the recovery room, the patient became hypoxemic and hypotensive and developed cortical blindness. The next day, a petechial rash was evident. Gurd's criteria for fat embolism syndrome were fulfilled. Her symptoms resolved over a 2-week period. Patients undergoing cementless THA are at risk for fat embolism syndrome, and this must be considered in the differential diagnosis for postoperative hypoxemia and neurologic deficits.