Background: Chylothorax is a rare complication after adult cardiovascular surgery. Chylothorax directly affects postoperative course and morbidity. Methods: Data for this prospective study was collected between July 2017 and August 2021. Twenty patients who had adult cardiac surgery were included in our study. Demographic characteristics, operative and postoperative data were collected and analyzed. Somatostatin injections were used to control chyle leakage. Failure of conservative treatment was the indication of surgery. Results: This study included 20 patients, 13 males and 7 females, who recently underwent adult cardiovascular surgery. The mean age was 47.7±13.27 years. The mean duration for chyle effusion was 4.35±1.98 days, while the mean duration of drainage was 12.15±2.56 days. Analysis of pleural fluid revealed mean pH value = 7.3±0.05, mean total protein =2.7±0.3 g/dL, mean pleural glucose concentrations =123±33 mg/dl, mean cholesterol level =43±17 mg/dL, mean triglyceride level =489±39 mg/dL, and mean chylomicron level =7±0.4 mg/dl. There was a statistical significance regarding the response of postoperative chylothorax to somatostatin therapy (p=0.001). Surgery (mass ligation) was indicated in 4 cases secondary to failure of conservative treatment. There was a significant difference between ICT drainage/day in patients who were managed conservatively and those who were managed surgically (p =0.0001). Conclusion: Chylothorax is more common following CABG and Aortic arch surgeries, and it has a significant impact on the postoperative course and morbidity. The diagnosis and therapy should be initiated as soon as possible. Conservative management is feasible in 80% of cases.