The patient is a 37-year-old Chinese male. In April 2014, he was diagnosed with brucellosis due to fever and fatigue, and his symptoms disappeared after anti-brucellosis medications for three months. In October 2014, the patient developed left hip pain, worsened by weight-bearing, and was admitted to the orthopedics department of our hospital in December 2014 due to the deterioration of symptoms. He is a sheep herdsman without any history of trauma, alcoholism, or hormone use. Physical examination revealed that the active and passive motion of the left hip was somewhat restricted due to pain. X-ray demonstrated that the left femoral head exhibited a strip-like low-density area but no evidence of stenosis (Figure 1A and B). CT scan revealed cavity necrosis in the left femoral head (Figure 1C). MRI revealed necrosis of the left femoral head, and effusion in the left joint cavity (Figure 1D and E). Blood test showed WBC 6.85 x 109/L with neutrophils accounted for 61.8%, CRP 3.5 mg/L, ESR 2.00 mm/h. SAT was positive at a titer of 1:320, and all tests for tuberculosis and rheumatoid arthritis were negative. Having been diagnosed with brucellar hip arthritis complicated by osteonecrosis of the left femoral head, the patient underwent puncture and irrigation of the left hip joint and core decompression and bone grafting. B. melitensis was detected in hip joint effusion and osteonecrosis of femoral head by real-time PCR. HE staining of a core biopsy of the left femoral head revealed amorphous necrotic material (Figure 2A); Giemsa staining can demonstrate scattered positive Brucella (Figure 2B). Triple anti-infective therapy was administered after the operation: rifampicin (0.6g po qd; Guangdong Hengjian Pharmaceuticals), doxycycline (0.1g po bid; Jiangsu Lianhuan Pharmaceuticals), and levofloxacin (0.2g ivgtt bid; Yangtze River Pharmaceuticals). Upon discharge from the hospital two weeks after the operation, his left hip pain was substantially relieved, and the antibiotic regimen was adjusted to rifampicin (0.6g po qd; Guangdong Hengjian Pharmaceuticals) and doxycycline (0.1g po bid; Jiangsu Lianhuan Pharmaceuticals) for six months. In follow-up, the symptoms of left hip pain and movement limitation disappeared almost half a year later, and there was no obvious abnormality in the blood test or hip X-ray (Figure 1F). In the telephone follow-up in April 2022, the patient's recovery proceeded well.