BackgroundHip replacement is generally conducted in those with prolonged arthritis pain or hip fractures, and postoperative infection is a serious complication. Mycoplasma hominis, belonging to mycoplasma species, exists mainly in the genitourinary tract. M. hominis infection after total hip replacement was rarely documented in literature.Case presentationA 59-year-old male was febrile after left total hip replacement. Empiric therapy with cefepime for suspected infection was ineffective. Specimens at the infection site were collected for culture, and pinpoint colonies grew after incubation at 35 degrees C for 48h on blood agar plate. They grew to approximately 0.5mm colonies in diameter after 7-day incubation, and were identified as M. hominis. Sequentially, combination therapy with clindamycin hydrochloride and moxifloxacin was initiated, and the patient defervesced within 3days and was discharged home.ConclusionsThe study highlighted the potential pathogenicity of M. hominis in postoperative infection. The possibility of this microorganism involvement should be valued if the patients who experienced the hip or joint replacement had inexplicable fever.