Background Pericardiectomy for post-radiation constrictive pericarditis has been reported to generally have unfavorable outcomes. This study sought to evaluate surgical outcomes in a large cohort of patients undergoing pericardiectomy for radiation-associated pericardial constriction. Methods A retrospective analysis of all patients (≥18years) who underwent pericardiectomy for a diagnosis of constrictive pericarditis with a prior history of mediastinal irradiation from June 2002 to June 2019 was conducted. There were 100 patients (mean age 57.2±10.1 years, 49% females) who met the inclusion criteria. Records were reviewed to look at surgical approach, extent of resection, early mortality and late survival. Results The overall operative mortality was 10.1% (n=10). The rate of operative mortality decreased over the study period; however, the test of trend was not statistically significant (P=0.062). Hodgkin’s disease was the most common malignancy (64%) for which mediastinal radiation had been received. Only 27% patients had an isolated pericardiectomy, and concomitant pericardiectomy and valve surgery was performed in 46% patients. Radical resection was performed in 50% patients, whereas 47% patients underwent a subtotal resection. Prolonged ventilation (26%), atrial fibrillation (21%) and pleural effusion (16%) were the most common post-operative complications. The overall 1,5- and 10-years survival was 73.6%, 53.4% and 32.1% respectively. Increasing age (HR 1.044, 95%CI 1.017-1.073) appeared to have a significant negative effect on overall survival in the univariate model. Conclusion Pericardiectomy performed for radiation associated constrictive pericarditis has poor long-term outcomes. The early mortality, though high (~10%), has been showing a decreasing trend in the test of time.