OBJECTIVE: Assess late cardiological evolution of children with rheumatic mitral regurgitation (RMR) who underwent mitral valve reconstructive surgery with implantation of Gregori’s ring (MVR), from 1987 to 2003. METHODS: A study was conducted to analyze a series of cases of 43 children with RMR who underwent MVR with ages ranged from five to twelve years (mean age 9.7 ± 2.2 years); 25 of the patients were females (58.1%). Patients were evaluated as per the following clinical parameters: functional class of heart failure, heart auscultation, electrocardiogram, chest X-ray and echocardiographic findings. RESULTS: Forty-three patients underwent preoperative evaluation during the postoperative period, the number of patients evaluated decreased to 31 due to the fact that 6 patients had died and 6 others underwent valve replacement surgery. Follow-up was carried out for 100% of the patients. A significant reduction of heart failure functional class was observed. Mitral systolic murmur became lesss intense during the postoperative period. The cardiac area on chest X-ray and the presence of left ventricular overload on electrocardiogram were reduced, as well as the mitral regurgitation level on echocardiographic study. After 188 months, the survival rate was 82%, and the annual mortality rate, 0.38%. Thirty-one (72.6%) patients did not require reoperation and the annual rate of patients who required further surgery was 0.51%. CONCLUSION: MVR is an effective procedure for treating RMR in children, resulting in a significant improvement of functional class, mitral systolic murmur and level of mitral regurgitation, as shown on Doppler echocardiogram.