Background: Women’s role in sanitation decision-making is often ignored area, due to their burden of household chores. There is limited evidence on women’s role in sanitation decision- making and its associated factors, particularly in the study area. Objective: To assess women’s role in sanitation decision making and its associated factors in Yilmana Densa District, West Gojjam Zone, Amhara Region, Northwest Ethiopia 2019. Methods: - A community based cross sectional study design was conducted in Yilmana Densa District from October 5 -November 25, 2019. Systematic random sampling technique was used to select 853 households which have latrine. Data was collected using a pretested questionnaire, observational check list, key informant, and focus group guides. Data was entered into Epi-data version 3.1 and exported to SPSS version 20.0 for analysis. Bivariate and multivariable logistic regressions were employed to identify factors associated with women’s role in sanitation decision making. Qualitative data analyzed by using opencoded Version 3.4.2703.16290 software. Thematic analysis was carried out. Results: - The magnitude of women’s role in sanitation decision making was 22% with (95%CI 20% to 25%) which is very low. Older women (≥45 years) [AOR= 1.85, 95% CI: (1.24, 2.76)], small family size ≤ 5[AOR=0.60, 95%CI: (0.41, 0.87)], having good knowledge [AOR= 0.57, 95% CI: (0.35, 0.93)] and having positive attitude [AOR= 0.34, 95% CI: (0.22, 0.51)] were statically significance with women’s role in sanitation decision-making and low economic status, burden of work at home, lack of formal education and power hierarchies within household were explored as challenges of women’s decision making role in sanitation. Conclusions: - The magnitude of women’s decision making role in sanitation was very low. Factors statistical significances with women's role in sanitation decision making were older women, small family size, good knowledge and positive attitude in sanitation decision making. Power hierarchies within the household, women’s attitude, low economic status, lack of formal education and burden of work at home were the explored challenges of women’s decision making role on sanitation. Therefore, the identified factors and challenges are the area of intervention to increase women’s role in sanitation decision making. Keywords: Women; sanitation; latrine construction; decision making; role; Ethiopi