Background: Breastfeeding is the recommended feeding method for infants due to its ease, health benefits, and cost-effectiveness. However, there is limited understanding of Exclusive Breastfeeding (EBF) in pastoral communities, such as the Sawena district in Ethiopia.

Objective: To assess the prevalence and factors associated with EBF among mothers with infants (aged 0-6 months) in pastoral communities in Southeast Ethiopia.

Method: A community-based cross-sectional study design with a convergent mixed-method approach was employed from March 01 to April 2023 G.C and involved 631 women selected through random sampling. Face-to-face interviews were conducted, and the data were analyzed using statistical software. Variables with a p < 0.25 in the analysis were included in the logistic regression model.

Results: Out of 631 eligible mothers, 625 participated in the study, resulting in 53.8% (95% CI; 49.8%-57.4%). prevalence of EBF in the study area. Factors significantly associated with EBF included household food security [AOR = 1.6, 95% CI (1.1-2.2)], ANC follow-up during pregnancy, [AOR = 5.3, 95% CI (2.4-11.9)], counselling about EBF during ANC visits [AOR = 5; 95% CI (2.1-11.7)], number of children [AOR = 1.6, 95% CI (1.1-2.3)] and attitudes toward EBF [AOR = 1.8; 95% CI (1.4-2.6)]. The qualitative findings revealed reasons for not practicing EBF, such as concerns about insufficient breast milk, concerns about the baby becoming thirsty, refusing solid foods later, or being negatively affected.

Conclusion: The prevalence of EBF in the Sawena district was lower than recommended. The influential factors include household food security, ANC follow-up, counselling during ANC, number of children, and attitudes toward EBF.