BACKGROUND: Mitral valve repair for rheumatic mitral valve disease in children has become the preferred surgical modality. A mitral valve ring is frequently used in the repair. A recently introduced biodegradable ring has shown promising results and allows for growth of the native annulus. METHODS: Between January 1994 and March 2006, 220 children underwent mitral valve repair for rheumatic valve disease. Mitral valve insufficiency was predominant in 198 patients (90%). Fifty-seven patients (26%) had associated aortic valve insufficiency and 51 (23%) had tricuspid valve insufficiency addressed during the same surgery. A mitral valve ring was used in 213 patients (173 Carpentier-Edwards and 40 biodegradable rings). Ninety-two percent (202 of 220) were in New York Association class III to IV. Echocardiography was performed at 6 months and thereafter once yearly. RESULTS: There were no hospital deaths or major postoperative morbidity. Follow-up was complete in 96% (212 of 220). One late death occurred. Mean follow-up was 76.4 months (range, 1 to 13 years). One patient (0.5%) had immediate mitral valve repair failure and required mitral valve replacement. Twelve patients (5.5%) required reoperation during follow-up. Recurrent mitral valve insufficiency/stenosis-free survival was 94.5% at 5 years and 92.7% at 10 years. Mean gradient was 5.2 +/- 1.9, 6.2 +/- 2.0, and 7.0 +/- 2.3 mm Hg, respectively, at 7 days, 6 months, and 1 year postoperatively for the Carpentier-Edwards ring and significantly lower (p < 0.001) for the biodegradable ring at 2.8 +/- 0.5, 3.1 +/- 0.7, and 3.3 +/- 0.5 mm Hg, respectively. Unchanged mean gradient during the first year was 65% (26 of 40) for the biodegradable ring and 21% (31 of 147) for the Carpentier-Edwards ring. CONCLUSIONS: Mitral valve repair in children with rheumatic valve disease has excellent immediate results with low operative risk and satisfactory midterm results and should therefore be the preferred treatment of choice. The use of biodegradable mitral valve ring results in a significant lower mean gradient during the first year of implantation compared with the Carpentier-Edwards ring and is available in a wide range of sizes.