To better understand the risk of developing a mental health disorder and the association on outcomes in endometrial cancer patients. Endometrial cancer patients ≥18 years old diagnosed between 1997–2012 were identified from the Utah Population Database and matched with up to 5 cancer free women from the general population. Mental health disorders were identified by International Classification of Diseases ICD-9 diagnostic codes. Endometrial cancer survivors with pre-existing mental health issues were excluded. Diagnosis of a mental health disorder in endometrial cancer patients was compared with the endemic rate. The impact of a mental health disorders on overall survival (OS) and cause specific survival (CSS) was evaluated. There were 2941 endometrial cancer patients and 12,192 general population matched subjects that met criteria with a median follow up time of 7.1 years (range 0–19.2) and 7.7 years (0.4–19.2) respectively. Within the first 1.5 years from diagnosis, there was an association of endometrial cancer patients being diagnosed with a mental health disorder (Hazard radio (HR) 3.09, 95% confidence interval (CI) 2.66–3.59). However, no association was found in endometrial cancer patients being diagnosed with a mental health disorder between 1.5–3 years (HR 1.07, 95% CI 0.83–1.38) and ≥3 years (HR 1.09, 95% CI 0.95–1.26). Treatment with tri-modality (surgery, radiation and chemotherapy) and advanced disease was associated with mental health disorders. OS was worse in endometrial cancer survivors who developed an anxiety disorder (p = 0.0265). CSS was worse in endometrial cancer patients diagnosed with all mental health disorders and anxiety disorders (p < 0.0001, p = 0.002). Endometrial cancer patients have an increased diagnosis of mental health disorders within the first 1.5 years of cancer diagnosis compared to the general population. Endometrial cancer survivors with anxiety disorder have worse OS. Anxiety disorders and all mental health disorders have a worse CSS.