A 54-year-old man, who had undergone continuous artificial dialysis for the previous 20 years because of nephronophthisis, underwent a renal transplant at our hospital. After the transplant, he was treated with an immunosuppressive drug (Prograf; 1 mg/day) and a steroid (Predonine; 5 mg/day). The patient was subsequently diagnosed with lumbar spinal-canal stenosis, and strongly requested surgical treatment because of poor quality of life, including lower back pain and intermittent claudication occurring approximately every 5 min. We performed an L3/4 lumbar posterior decompression and posterior lumbar interbody fusion (with use of autogenous bone). The lower back pain was improved after the surgery, but the patient developed a fever 1 week after the surgery. An intensity change in a magnetic resonance imaging (MRI) scan was recognized within the L3/4 intervertebral disk. An extensive subcutaneous hematoma, which extended into a deep surgical site, was identified. A lumbar puncture of this site was positive for MRSA-positive on bacterial culture, and the patient was diagnosed with post-spinal fusion MRSA vertebral osteomyelitis. At the same time, we checked the linezolid sensitivity, which was positive, and MIC. And it was positive. We therefore performed emergency flushing and debridement and began linezolid treatment (1200 mg/day, divided) immediately after the surgery. However, we did not opt to remove the pedicle screw inserted previously for the purpose of fixation because of the risk of secondary osteoporosis due to long-term systemic use of a steroid. Throughout the course of linezolid treatment, the C-reactive protein (CRP) level gradually decreased, becoming negative 4 weeks after administration started. Serum creatinine (Cr) concentration was approximately 1.3 mg/dL during the treatment period, indicating no deterioration in renal function. Hemoglobin (Hb) level decreased from approximately 10–6 g/dL within 2 weeks of starting linezolid treatment, suggesting the development of bone marrow suppression. Fortunately, the infection had been stabilized by early treatment with antibiotics, and linezolid was replaced with a trimethoprim–sulfamethoxazole (TMP–SMZ) combination (320 mg TMP and 1600 mg SMZ) until the Hb level recovered, at which point linezolid use was re-instated. However, we did not administer a preventative antibiotic after the patient tested CRP-negative because of the risk of renal damage. Fortunately, infection has not recurred up to the present time (3 years after the operation).