Systemic lupus erythematosus (SLE) patients are at higher risk of developing opportunistic infections such as tuberculosis (TB), especially extrapulmonary forms like osteoarticular TB, compared to the general population. However, tuberculous sacroiliitis has been scarcely reported in these patients. We present a 34-year-old woman with SLE who developed articular tuberculosis simultaneously affecting the right sacroiliac joint and the left knee. The patient was successfully treated with antituberculosis therapy for nine months. In this case, in addition to the immunological abnormalities of lupus, the long-term glucocorticoid therapy at high dosages was the main risk factor for the development of osteoarticular tuberculosis.