Suppurative arthritis of the knee is a well known complication following intra-articular injection of steroids on the other hand, tuberculous arthritis following such injection is rare. From January, 1981 to April, 1986, 46 patients of tuberculous arthritis of the knee were admitted to Severance Hospital and Yong-Dong Severance Hospital of Yonsei University College of Medicine. Among them 22 patient (48%) had a history of intra-articular injection of steroids and we analyzed them. The results were as follows: 1. The average age was 48.6 years (3–71 years). And sex ratio was in 1:2.7 as female predominant. 2. Initial diagnosis before the steroid injection were osteoarthritis (13 patients), rheumatoid arthritis (6 patients), and traumatic arthritis (3 patients). The fifty percent of the patients were injected by the local practitioner and fourty five percent had a history of accupuncture and moxa cautery. The preoperative diagnosis (diagnosis on admission) were tuberculous arthritis (12 patients), pyogenic arthritis (5 patients), rheumatoid arthritis (3 patients) and osteoarthritis(2 patients). 3. The number of intra-articular injection ranged from 2 to 100 times (average 12.8) during periods ranging from 1 month to 4 years (average 19.2 months). And interval between last injection and confirmation of tuberculous arthritis ranged from 1 week to 2 years (average 7.0 months). 4. Eight patients (36%) had a active or inactive pulmonary tuberculosis. 5. The positive cultures of typical Mycobacteria tuberculosis were obtained from 11 patients 59%). 6. The modalities of treatment were synovectomy or curettage in 16 patients and arthrodesis in 6 patients. And all patients were treated by antibuberculous chemotherapy. In conclusion, we observed that tuberculous arthritis developed not infrequently after intra-articular injection of steroids. And we considered the causes of tuberculous arthritis following intra-articular injection of steroids were; 1) reactivation of dormant injection or hematogenous, spreed due to interferance of host defence mechanisms, 2) contamination by the instrument and equipment, 3) aggravation of preexisting tuberculous lesions. Whenever one try to inject the steroid into joint, bacterial culture foi the pyogenic organism including tuberculosis and fluid analysis from the joint fluid should be done before the injection. We recommend that other method for the confirmation for the tuberculosis is needle biopsy of the synovium. If the symptoms are not improved after injection or the joint shows inflammatory reaction, one must discontinue the injection and reexamine the joint fluid analysis and culture for the confirmation of the infection.