Background: Uterine prolapse is common, non-life-threatening, but has a negative impact on women psychosocial and economic life. Damage to levator ani muscle is the early onset of uterine prolapse, while the damage of sacrouterine ligaments aggravates the stage. The strength of sacrouterine ligament depends on tissue cellularity, the formation of collagen I/III ratio, and the decreased expression of elastin. The lower the ratio of collagen I/III, the higher the risk of stage III-IV uterine prolapse. The ratio of collagen I/III formation is allegedly influencing through the expression of estrogen receptor alpha, by increasing collagen III synthesis and decreasing the degradation. Objective: We aimed to investigate whether high estrogen receptor alpha and collagen III expression, and the low elastin expression in the sacrouterine ligaments were stage III-IV uterine prolapse risk factors. Method: In March to August 2014, a non-matching case control study was conducted in 3 hospitals in Denpasar, and the materials were processed in the Faculty of Veterinary Medicine Laboratory of Udayana University. The case was uterine prolapse stage III-IV, the control was the non-uterine prolapse. We collected 1.5 cm residual sacrouterine ligaments from the edge of the cervix fixed with 10% buffered formalin from patients who underwent a total hysterectomy. They were examined immunohistochemically to identify estrogen receptor alpha expression, collagen III, and elastin. Results: Our sample was 44, divided equally between the case and control group. Compared to the control, in the case group, the proportion was significantly higher for the high estrogen receptor alpha expression (OR=5.71, 95%CI 1.56-20.93, p=0.007), high collagen III (OR=6.50, 95% CI 1.64- 25.76, p=0.005), and low elastin (OR=5.40, 95%CI 1.37-21.26, p=0.012). Conclusion: the high expression of estrogen receptor alpha and collagen III and low expressions of elastin in sacrouterine ligaments served as stage III-IV uterine prolapse risk factors.