Purpose: To describe factors associated to parametrial involvement, and how these factors modify the prognosis of patients with endometrial carcinoma treated with radical hysterectomy.Basic procedures: It is an observational retrospective study in which categorized patients according to those with and without parametrial involvement. A descriptive analysis and then a comparative analysis were performed to find associations between parametrial spread and clinical, surgical, and pathologic variables.Main findings: We analyzed a total of 85 patients, out of which 18 (21.2%) had parametrial involvement. Pathology factors associated to parametrial involvement were the endometrioid subtype, grade 3, and variants of poor prognosis (OR 3.41, CI95% 1.09 – 10.64; p=0.035), myometrial invasion of greater than 50% (OR 7.76%, CI95% 1.65 – 36.44; p=0.009), uterine serosal involvement (OR 17.07, CI95% 3.87 – 75.35; p<0.001), ovarian metastasis (OR 5.15, CI95% 1.36 – 19.46; p=0.016), positive peritoneal cytology (OR 3.9, CI95% 1.04 – 14.77; p=0.044), and lymph node metastasis (OR 3.4; C95% 1.16 – 9.97; p=0.026). Five-year disease-free survival was 74% (CI95% 57.4 - 85.4) for the group without parametrial spread and 50.8% (CI95% 22.7 - 73.4) for the group with parametrial spread (p=0.001). Similarly, 5-year overall survival was 85.2% (CI95% 67.9 - 93.6) for the group without parametrial spread and 47.5% (CI95% 8.1 – 80.2) for the group with parametrial spread (p=0.002).Conclusion: Factors associated to parametrial involvement were histologies of poor prognosis, tumors that affect the uterine serosa, the cervix, or that spread beyond the uterus. Additionally, parametrial involvement directly affects prognosis by reducing overall survival, disease-free survival and increasing odds for recurrence.