Aim: The aim of this paper was to compare methods for the assessment of myometrial invasion in patients with endometrial cancer. We analyzed concordance between pelvic magnetic resonance imaging and intraoperative assessment of myometrial invasion performed by a pathologist and final histopathology. Materials and methods: We analyzed clinical material from patients with endometrial cancer who underwent primary surgical treatment in the Center of Oncology (Branch in Krakow) between 2012 and 2014. Pelvic magnetic resonance imaging with an assessment of myometrial invasion was performed preoperatively. During the procedure, the resected uterus was examined intraoperatively. We analyzed the concordance between the assessment of myometrial invasion in pelvic magnetic resonance and intraoperative assessment performed by a pathologist and final histopathological examination. Cohen’s kappa coefficient was used in the statistical analysis. Results: We analyzed medical history of 128 patients with endometrial cancer. The sensitivity of preoperative magnetic resonance imaging and intraoperative assessment was 81% and 84.11%, respectively. Cohen’s kappa coefficient was 0.61% and 0.655%, indicating substantial agreement. Both methods are more accurate in predicting <1/2 myometrial invasion. Intraoperative assessment of myometrial invasion showed higher sensitivity, but lower specificity compared to magnetic resonance imaging. Conclusions: Magnetic resonance and intraoperative evaluation by a pathologist show similar accuracy in the assessment of myometrial invasion. Clinical utility of both these methods for early assessment of myometrial invasion speaks in favor of intraoperative examination, which is a less expensive and faster method.