Background: The health benefits and economic gains of exclusive breastfeeding for the mothers and the new-born are well-documented in the literature as discussed in the background and the rationale for this study. The effectiveness of the social cognitive based interventions in promoting breastfeeding among women in general is also documented. However, there is lack of evidence regarding social-cognitive strategies that could be used to promote exclusive breastfeeding practices among primiparous mothers in Ethiopia means that current exclusive breastfeeding promotion interventions or strategies may not produce the expected outcomes. This assumption seems to be supported by low rate of early initiation of breastfeeding in country (52.1% instead of at least 75% as recommended by WHO) and shorter period of breastfeeding (one month) among mothers in Addis Ababa (CSA and ICF 2012) despite various strategies and interventions that have been implemented. Aims: The study was conducted with the aim of determining the social-cognitive predictors of exclusive breastfeeding among primiparous mothers during the first six months post-delivery with the view of developing social-cognitive strategies to promote exclusive breastfeeding practices among primiparous mothers in Addis Ababa, Ethiopia. Research design and method: The study was carried out within the quantitative positivist paradigm. The study was divided into two phases. The researcher used quantitative longitudinal, descriptive, exploratory and correlational designs to determine the social cognitive predictors of exclusive breastfeeding among primiparous mothers in Addis Ababa, Ethiopia within the first six months post-delivery. The results of the first phase assisted the researcher to design social-cognitive strategies to promote exclusive breastfeeding among primiparous mothers using a Delphi survey. A Delphi survey design was used to assist the researcher to develop the social-cognitive strategies to promote exclusive breastfeeding among primiparous mothers. It consisted of three rounds of mailed self-completion questionnaires. The Delphi was supported with critical review and synthesis of literature throughout the strategies’ development process. Descriptive summary statistics were used to analyse the prenatal breastfeeding behaviour of 141 primiparous mothers followed from the last antenatal care visits up to six months after delivery. Bivariate correlational and multiple logistic regression analyses were used to identify the social cognitive determinants and predictors of exclusive breastfeeding within the first hour post-delivery and six months thereafter. Findings: Positive breastfeeding outcome expectancy and high breastfeeding self-efficacy were identified as the independent social cognitive predictors of exclusive breastfeeding among primiparous mothers in Ethiopia. These predictors were used to develop social cognitive strategies to promote exclusive breastfeeding, which comprise six main components: (1) scientific evidence for the strategies, (2) the rationale for the strategies, (3) the aim of the strategies, (4) the scope of the strategies, (5) the guiding principles, and (6) the key results areas. These strategies were developed and validated with the inputs from 37 experts on breastfeeding and social cognitive theory. Two key results areas (build individual capacity for exclusive breastfeeding and create an enabling environment) and five strategic objectives were formulated and validated. Conclusions: The successful implementation of the social cognitive strategies to promote exclusive breastfeeding among primiparous mothers in Addis Ababa, Ethiopia as described above will require among others (1) in-service training on social cognitive skills for healthcare providers with focus on how to build self-efficacy and outcome expectancy, (2) the development of self-efficacy and outcome expectance assessments tools relevant to the Ethiopian context, and (3) additional support and resources from the healthcare managers. Recommendations: To the researcher recommend that programs aimed at promoting exclusive breastfeeding practices among primiparous mothers should be based on the combined attributes of positive social cognitive outcome expectance and high breastfeeding self-efficacy. Further research is needed to develop assessment tools for breastfeeding self-efficacy and outcome expectancy before the implementation of the proposed strategies. / Health Studies / D. Litt. et Phil. (Health Studies)