Objective To investigate the cost and impact of routine preoperative computed tomography (CT) in patients with high‐grade endometrial cancer, and its role in identifying extrauterine disease. Methods We retrospectively identified patients with high‐grade endometrial cancer who underwent routine CT scan prior to surgical procedure between September 1, 2005, and January 31, 2015. Cases in which CT findings led to alterations in the treatment plan were documented. Incidental findings unrelated to endometrial cancer diagnosis were captured. Cost of imaging and diagnostic procedures was based on Ontario's Physician Services–Schedule of Benefits. Results Of 179 patients included, 57 (31.9%) were diagnosed with stage 3–4 disease. CT showed evidence of metastatic disease in 30 (16.8%) patients; however, planned surgical procedure was altered in only nine (5.0%) cases. CT results showed incidental findings requiring follow‐up in 78 (43.6%) cases, three of which were second malignancies. We estimate an expenditure of CAD$14 185.85 on routine imaging for every case in which surgical management was changed. Conclusions Preoperative CT imaging is efficacious in identifying extrauterine disease in patients with high‐grade endometrial cancer, although it seldom alters surgical management. Many of these CT scans will identify incidental findings requiring further interventions, resulting in substantial costs.