Background: Chronic tenosynovitis of the wrist and hand is commonly seen by orthopedists, especially hand surgeons. However, cases with rice body formation are comparatively rare. Thus, we retrospectively reviewed the cases of chronic tenosynovitis in our department and evaluated the necessity of antibiotic therapy in the early post-surgical stage. Methods: We analyzed the medical and surgical records of patients who had undergone surgery for chronic tenosynovitis with rice body formation in our department from 1997 to 2015. We evaluated the causes of chronic tenosynovitis, culture findings, pathological findings, and post-operative treatment courses. Results: Nineteen patients with 23 involved hands underwent surgery for chronic tenosynovitis, and 9 patients had rice body formation. The most common cause of chronic tenosynovitis was non-tuberculous mycobacteriosis, and other causes were fungal infection and infection of unknown origin. Recurrence was observed in 2 cases of mycobacteriosis and 1 case of fungal infection; 1 case of mycobacteriosis also had a re-recurrence. Conclusions: In the diagnosis of chronic tenosynovitis with rice body formation, it is necessary to consider not only non-tuberculous mycobacteriosis, but also fungal infection as its origin. However, it is difficult to define the cause of synovitis, but in cases in which these infections are suspected, anti-bacterial therapy in the early post-surgical period could be effective.