This study aimed to identify the priorities of the factors affecting family planning practices in Ethiopia, with the ultimate aim of providing evidence to the Ethiopian government and international organizations for establishing family planning policies or family planning-related project plans. Multi-stage, clustered, stratified random sampling was performed on a total of 35,479 men aged above 15 years and women of childbearing age (15-49 years) in two metropolitan cities and five regions of Ethiopia. The survey was conducted by face-to-face interview using Tablet PC, and 25,972 responses, excluding censored data were included in the final analysis. The collected data were first analyzed using the Pearson chi-square test, independent sample t-test, and F-test with the Tukey HSD method as a post-hoc. Second, a decision-making tree analysis was conducted to identify priority factors affecting the decision to implement family planning The primary factor affecting the family planning practice was 'spouse or sexual partner's support for family planning (P <.001)'. 'Region (p <.001)' was the second priority factor for both the group receiving 'support for family planning by spouse or partner' and the group not receiving it. The third priority factors appeared differed by region in both groups. It is necessary to establish family planning policy and program plans targeting both men and women, and participation of religious and community leaders is considered important in the establishment process. In addition, it is considered necessary to enhance the professionalism by dividing the education and evaluation process for HEW to provide high-quality counseling, education, and services on family planning at the community level.