Ovarian cancer (OC) is the fifth most common cancer in women and has become the main cause of gynecologic malignancy death. The incidence rate of OC increase and overall survival (OS) is relatively low because most of patients are diagnosed at advanced stages. Serous ovarian cancer (SOC) is the most frequent histopathological type and often occurs at late stage. Stage and optimal treatment are independently associated with chemo-response in SOC. FIGO staging system in SOC can provide prognostic information and guidance on personalized management of ovarian cancer. Cancer stem cells (CSC) are pivotal players in SOC progression and prognosis. CD133 and ALDH1A1 are related CSC markers in SOC. This study aimed to investigate the expression of CD133 and ALDH1A1 in SOC and their correlation with FIGO stage. This research was carried out as analytic-observational with cross-sectional design using paraffin block of patients diagnosed with SOC in the Department of Anatomic Pathology Hasan Sadikin Hospital Bandung. Samples were divided in two groups: early stage (FIGO stage I and II) and advanced stage (FIGO stage III and IV). All samples were stained by immunohistochemistry CD133 and ALDH1A1. All data were analysed using Chi-Square test with significant level 5%. The results of this study showed that there was correlation between expression of CD133 with FIGO staging in SOC (p value 0.004) and there was no correlation between expression of ALDH1A1 with FIGO staging in SOC (p value 0.197). It can be concluded that higher CD133 expression showed higher tumour cells ability to do invasion and metastasis and had higher influenced FIGO stage.