Background Chylothorax after pediatric cardiothoracic surgery is associated with increased morbidity and resource utilization. There is limited data on optimal management of chylothorax as well as effectiveness of individual components of previously reported management protocols. A chylothorax clinical management protocol was implemented at Advocate Children’s Hospital as a quality improvement initiative with the primary objective of determining the association of protocol implementation with chest tube duration. Secondary objectives were to determine the association of individual protocol elements with chest tube duration. Methods The clinical management protocol was developed by a multidisciplinary work group after reviewing internal practice patterns as well as published data. Patient data was compared 21 months before and 21 months after implementation of the protocol in April 2019. Data collected included patient demographics, chest tube duration, and medical and dietary interventions such as use of steroids and low fat diet. Outcomes analyzed included death, surgery, duration of chest tube, and hospital length of stay. Results A total of 15 and 27 patients were analyzed before and after protocol implementation respectively. There was no significant difference in demographic data. Protocol adherence was 96%. Methylprednisolone was used exclusively after protocol implementation. Patients tended to receive lower maximum doses of furosemide and chlorothiazide after protocol implementation. Multivariable analysis showed that duration of chest tube after onset of chylous output decreased by 3 days after protocol implementation. A cutoff of 10 mL/kg per 24 hours of chest tube output was shown to predict high volume chest tube output above the median. Conclusion A chylothorax management protocol was associated with a 3-day decrease in chest tube output in pediatric cardiac patients. Review of the protocol components demonstrates that a 5-day course of steroids may be beneficial while a low-fat diet may not. This initiative demonstrates how a quality improvement initiative can be successfully utilized in the clinical setting and provide not only protocol level data but also component-specific data.