Background: The reported outcomes of pediatric dilated cardiomyopathy (DCM) have varied across studies. There are few outcome data concerning DCM in Chinese children. Therefore, we conducted a retrospective study to describe clinical features and determine risk factors for poor outcomes in children with DCM. Methods: We enrolled 121 children with DCM in our hospital from 2003 to 2021. General information and laboratory and echocardiographic data were collected and analyzed. Cox regression analysis was performed to determine risk factors for poor outcomes. Results: This study included 121 patients (69 males and 52 females). The median age at diagnosis was 10.8 years, and the follow-up time was 10.0 months. Eighty-two patients (67.8%) exhibited cardiac function classes III–IV at the time of diagnosis. Tachypnea was the most common symptom (78.5%). In echocardiography, the mean left ventricular end-diastolic dimension z score was 7.36 ± 2.73, and the left ventricular ejection fraction z score was −6.58 ± 2.17. The 1-, 2-, and 5-year survival rates were 51.2%, 43.8%, and 32.2%, respectively. Cox analysis revealed that cardiac function classes III–IV (hazard ratio [HR] = 1.801, 95% confidence interval [95% CI] = 1.030–3.149, p = 0.039) and calcium levels (HR = 0.219, 95% CI = 0.084–0.576, p = 0.002) were predictors of poor outcomes in children with DCM. Conclusions: Children with DCM are at high risk of death. Cardiac function class III–IV and calcium levels were related to the prognosis of pediatric DCM patients.