Background: Optimal breastfeeding is so critical that it could save the lives of over 820,000 children under the age of five years each year. For optimal growth, development, and health, the WHO recommends Exclusive Breastfeeding (EBF) in the first six months. To ensure nursing mothers breastfeed their children exclusively, they should also have access to skilled practical help to build mothers’ confidence and prevent or resolve breastfeeding problems. Interventions promoting optimal Infant and Young Child Feeding practices could prevent 19% of under-five deaths, and such intervention could improve nursing mothers’ understanding and practice of EBF. Objective: This trial is designed to formulate a hospital-based counseling guide on EBF, implement it, and determine its effect on improving EBF practice in Anambra State, Nigeria. Methods: The study is a cluster randomized controlled trial conducted in selected hospitals in Anambra State, Nigeria. Based on inclusion criteria, 12 hospitals that offer comprehensive ante-natal and post-natal clinic services and have a higher population of women assessing care in the ante- and post-natal clinics were selected for the study. Six hospitals each were randomized to either the intervention or the control arm. The intervention hospitals received the formulated hospital-based counseling guide and the hospital’s usual care, while the control hospitals received only the hospital’s usual care. Statistical analysis will be conducted using Statistical Package for Social Science (SPSS version 25). Descriptive statistics will be used to summarize and present demographic and clinical characteristics. Categorical variables will be expressed as frequencies or percentages and quantitative variables as means, standard deviations, median, and interquartile ranges. An intention-to-treat analysis will be conducted.