The aim of the study was to develop strategies to reduce the unmet need for modern contraception among agro-pastoral women. The objectives of the study were to determine the prevalence of unmet need for modern contraception, determine the factors associated with unmet need for modern contraception, and explore the barriers that hindered agro-pastoral women from using modern contraception. A mixed-method research design was used to conduct the study. Data were collected from agro-pastoral women and family planning service providers. Questionnaire and individual in-depth interviews were used to collect the data. The validity and reliability of the quantitative data and trustworthiness of the qualitative data were ensured. Use of standard data collection tools, employing method and data triangulation, and documenting all the procedures of data collection and analysis were among the ways employed to do so The quantitative data were analysed using simple descriptive statistics and multivariate logistic regression. Thematic analysis was employed to analyse the qualitative data. Ethical principles of research such as beneficence, justice, informed consent, respect for persons, privacy and confidentiality and scientific integrity were considered to conduct the study. The study revealed an unmet need of 29.2% (n=112) for modern contraception among agro-pastoral women. The unmet need for birth spacing constituted 21.1% (n=81), whereas the unmet need for birth limiting was 8.1% (n=31). The age of the women, the number of living children, knowledge of modern contraceptive methods, and knowledge of FP service centres were found to be associated with women‘s unmet need for modern contraception. Lack of time and money, lack of knowledge about modern contraception, and fear of side effects were the major individual-level barriers. There were also culture-related factors such as the need for many children that hindered agro-pastoral women from using modern contraception. Moreover, the study disclosed that religious unacceptability and husband‘s and relatives‘ opposition were also among the mentioned barriers. The quality of FP service provision in terms of the competence and behaviour of health service providers, unavailability and inaccessibility of FP service, were also indicated as barriers. The findings informed the development of strategies to reduce agro-pastoral women‘s unmet needs for modern contraception in Eastern Ethiopia. The study further recommended that the health bureaus of the region, zone and district collaborate in ensuring that agro-pastoral women realise the significance of the provision of accessible, equitable, quality modern contraception. It is also essential to equip health facilities with qualified health service providers and necessary facilities. Religious leaders should be involved in disseminating vital, relevant and empowering FP information. / Health Studies / Ph. D. (Public Health)