Objective To evaluate the functional status of pediatric patients undergoing congenital heart surgery after discharge from the intensive care unit, and to evaluate the correlations among clinical variables, functional status and surgical risk. Methods Cross-sectional study including patients aged 1 month to less than 18 years undergoing congenital heart surgery between October 2017 and May 2018. Functional outcome was assessed by the Functional Status Scale, surgical risk classification was determined using the Risk Adjustment for Congenital Heart Surgery-1 (RACHS-1), and clinical variables were collected from electronic medical records. Results The sample comprised 57 patients with a median age of 7 months (2 - 17); 54.4% were male, and 75.5% showed dysfunction, which was moderate in 45.6% of the cases. RACHS-1 category > 3 was observed in 47% of the sample, indicating higher surgical risk. There was a correlation between functional deficit and younger age, longer duration of invasive mechanical ventilation and longer intensive care unit stay. Moreover, greater functional deficit was observed among patients classified as RACHS-1 category > 3. Conclusion The prevalence of functional deficit was high among children and adolescents with congenital heart disease after cardiac surgery. Higher surgical risk, longer duration of invasive mechanical ventilation, longer intensive care unit stay and younger age were correlated with worse functional status.