Objective: Ovarian cancer has a high incidence and a high mortality rate, and often found in terminal stage. In ovarian malignancy, one of the important proteins presents in the apoptosis process is Caspase-3. Caspase-3 has an important role in modifying the cell morphologic and several biochemistry condition of the apoptosis process. Our study aims to analyze the correlation between Caspase-3 expression and the cell differentiation grade, the stage of the disease, and the residual tumor size after primary surgery in epithelial ovarian cancer. Method: We conducted a cross-sectional study. The sample was recruited in Dr. Soetomo Hospital Surabaya. They were ovarian cancer patients with complete medical records, which ovarian tumor specimens were deparaffinized in the pathology anatomy laboratory, Faculty of Medicine, Airlangga University, Surabaya, Indonesia. Patients who received a chemotherapy or a radiotherapy before the surgery, or whose paraffin wax embedded tissue was damaged were excluded. The Caspase-3 expression was examined immunohistochemically. The correlation among the variables were analysed using the Spearman and Phi correlation test. Results: From 42 patients, Caspase-3 expression was positive in the 47.6%, while the 52.4% was negative. It was found that most samples with a good grade of cell differentiation showed a positive Caspase-3 expression (r=-0.215, p<0.05). Moreover, in most samples with the early stage of the disease had a positive Caspase-3 expression (Ï†=-0.583, p<0.05). In addition, most samples with residual tumor less than 1 cm in diameter, also showed a positive Caspase-3 expression (Ï†=-0.336, p=0.029). Conclusion: A statistically significant negative correlation was present between Caspase-3 expression and the cell differentiation grade, the stage of the disease, and the residual tumor after the primary surgery.