Introduction: Serous endometrial intraepithelial carcinoma (SEIC) is a rare diagnosis, defined as an intraepithelial lesion with cells identical to serous type endometrial carcinoma. SEIC is considered to be potentially metastatic, however clear and robust data on prognosis are lacking, potentially leading to variability in clinical management. Objective: The aim is to establish the opinion of gynecologists on the optimal management of patients with SEIC. Methods: An online questionnaire with 15 multiple choice questions was sent to all gynecologists with expertise in gynecological oncology in 19 expert centers in The Netherlands. Results: A total of 24 gynecologists participated. The majority of respondents (n = 18/24, 75%) do not consult a guideline regarding the treatment of SEIC. In current practice, 14 of the 24 respondents perform surgical staging in women with SEIC (58.3%) while seven choose hysterectomy with bilateral salpingo-oophorectomy (29.2%), and three (12.5%) have no firm preference. Eleven of the 14 respondents who perform a surgical staging procedure believe that this is certainly the optimal treatment. The majority of respondents have no firm opinion on whether lymph node sampling or lymph node dissection is preferable during surgical staging (n = 15/23, 65.2%). Most respondents do not give adjuvant therapy (n = 15/24, 62.5%), 25.0% recommend brachytherapy (n = 6/24). Follow-up is for 5 years in almost all cases (n = 23/24). Conclusion: There is no consensus on the optimal surgical treatment and the use of adjuvant therapy for patients with SEIC. Our research team is therefore conducting a nationwide cohort study in which treatment modality, morbidity and survival will be evaluated.