Severe mitral regurgitation predicts poor outcomes in adults with left ventricular dysfunction. Frequently, adult patients now undergo initial mitral valve surgery instead of heart transplant. Pediatric data are limited. This study evaluates the efficacy of mitral valve surgery for severe mitral regurgitation in children with dilated cardiomyopathy. This is a single-institution experience in seven children (range, 0.5-10.9 years) with severe mitral regurgitation and dilated cardiomyopathy who underwent mitral valve surgery between January 1988 and February 2005, with follow-up to January 2006. Children with dilated cardiomyopathy had a depressed fractional shortening preoperatively (24.4% +/- 6.1%) that remained depressed (22.9% +/- 7.6%) 1.3 +/- 1.2 years after surgery (p = 0.50). Left ventricular end-diastolic (6.5 +/- 1.5 to 4.8 +/- 1.8 z-scores, p < 0.01) and end-systolic (6.8 +/- 1.5 to 5.5 +/- 2.1 z-scores, p < 0.05) dimensions improved. Hospitalization frequency had a median decrease of 6.0 hospitalizations per year (p < 0.02). Three patients were transplanted 0.2, 2.4, and 3.5 years after surgery. There was no perioperative mortality. Mitral valve surgery in children with dilated cardiomyopathy was performed safely and improved symptoms, stabilizing ventricular dysfunction in most patients. Mitral valve surgery should be considered prior to heart transplant in children with dilated cardiomyopathy and severe mitral regurgitation.