A 69-year-old male patient, 5 years after a well-functioning total hip arthroplasty for severe osteoarthritis, presented with a 3-month history of progressive, unrelenting, "burning" pain in his right hip with accompanying fullness of the right thigh. Inflammatory markers were elevated, and imaging revealed a large unilocular fluid collection with communication to the hip joint. Aspiration was positive for Mycobacterium senegalense. A combination of surgical and antibiotic therapy successfully treated this patient.Mycobacterium senegalense is a rare cause of prosthetic joint infection. A combination of surgical and antimicrobial management is required for effective treatment.