Dissertation (MSc Paediatric Nursing)BACKGROUND: Pneumonia and Diarrhea are the most common childhood illnesses and are the leading cause of high childhood morbidity and mortality in Manyara Region. EBF is known to be able to protect infants against these illnesses, however not much is known about the breastfeeding practices in Manyara Region and how much it contributes to pneumonia and diarrhea. Objective: This study aimed at determining the association between EBF with pneumonia and diarrhoea among infants aged 0 to 6 months born to women from pastoralists and hunters community in Manyara Region. Methods: This was a community based cross sectional analytical study, with a quantitative approach. Data was collected by using interviewer- administered questionnaire. Purposive sampling was done to select the region and multistage sampling was used to select districts, wards, villages and households. Data were analyzed using statistical package for social sciences (SPSS) version 20, and findings were presented in tables, figures, frequencies, percentages, chi-square, Odd Ratio (OR) and Adjusted Odd Ratio (AOR). Results: Out of 342 infants who were investigated, 42.4% (145) were having good breastfeeding practices and were still on EBF at the time of the study. The factors which were reported to influence EBF were maternal knowledge [AOR 0.086; p=0.001; 95% CI 0.028-0.548], ANC attendance [AOR 1.154; p=0.005; 95% CI 1.023-3.042] and social cultural factors [AOR 0.254; p=0.017; 95% CI 0.024-0.786] Prevalence of Pneumonia and Diarrhoea was 16.7% and 8.5% respectively. The results showed that there was a significant association between pneumonia and infants age 4-5 months [AOR 1.429; p= 0.014; 95%CI 1.373-4.836], unsupportive social-cultural standards about EBF [AOR 2.625; p= 0.012; 95%CI 1.234-5.575] and poor breastfeeding practices [AOR 9.314; p= 0.011; 95%CI 1.236-14.376] after controlling for confounders. However, Breastfeeding practices was not associated with diarrhea after controlling for cofounders [AOR 1.889; p= 0.524; 95%CI 0.293- 3.534]. Conclusion: Exclusive breastfeeding is still low among infants of pastoralists and hunters community in Manyara Region which could be attributed to inadequate knowledge, unsupportive social-cultural standards and failure to attend recommended ANC visits, thus contributing to occurrence of childhood pneumonia.