Background: Radioembolization with yttrium microspheres is an established therapeutic modality for primary and secondary hepatic malignancies, with studies demonstrating improved overall survival. There remains a paucity of data on cholecystitis as a complication of radioembolization. We describe a small series of patients who developed cholecystitis as a result of radioembolization. Methods: Patients who had developed cholecystitis as a complication of radioembolization in our institution between 2001 and 2012 were retrospectively reviewed. Patient demographics, cancer details including treatment history, and procedural details of radioembolization and complications of cholecystitis were collected. Results: Of 74 patients who underwent radioembolization using yttrium-90emitting microspheres, four (5.4%) presented with acute cholecystitis as a result of their treatment. All patients presented over 4 weeks following radioembolization and did not settle with conservative treatment. At surgery, the gallbladder was fibrotic and contracted in all cases making surgery difficult. Conclusion: The incidence of symptomatic radiation cholecystitis after radioembolization is low, and prophylactic cholecystectomy is not routinely recommended for patients undergoing radioembolization. Radiation cholecystitis should be suspected in patients presenting with symptoms of biliary colic or cholecystitis following radioembolization. Early cholecystectomy can be considered in patients undergoing surgery for other indications, especially in high-risk surgical patients in whom there is a high likelihood of radioembolization in the future as they do not respond to conservative treatment.