This paper explores two prominent nursing theories—Meleis' Transition Theory and Mercer’s Maternal Role Attainment Theory—highlighting their theoretical underpinnings, concepts, and clinical applications. Meleis’ Transition Theory provides a comprehensive framework to support individuals undergoing significant life changes, such as illness, parenting, or hospital discharge. It emphasizes the universal nature of transitions, requiring nurses to offer care during critical milestones, fostering healthy coping and adaptive outcomes. The theory underscores the importance of understanding disruptions, critical points, and skill acquisition in navigating transitions, aiming to develop interventions that ensure positive experiences and well-being. In contrast, Mercer’s Maternal Role Attainment Theory focuses specifically on the maternal role, outlining a process of identity development through four stages: commitment and preparation, acquaintance and learning, normalization, and maternal identity achievement. This theory emphasizes the bond between mother and child and the vital role of nursing in facilitating this bond. Key concepts include the maternal self, environmental influences, health, and the integral role of nursing in promoting family well-being through education and support. A clinical scenario involving a rural woman with ten children highlights the application of both theories. Meleis’ Transition Theory guided counseling interventions addressing the couple’s resistance to family planning by leveraging moral and religious grounds. Simultaneously, Mercer’s Maternal Role Attainment Theory supported the mother’s education on neonatal care, maternal health, and family well-being. The comparison revealed that Mercer’s theory offers a more structured approach to addressing maternal health, empowering mothers, and fostering better long-term outcomes for families. This comparative analysis underscores the significance of theoretical frameworks in nursing practice, validating the integration of evidence-based approaches to improve maternal and neonatal health. By aligning clinical practice with these theories, nurses can enhance caregiving, strengthen family systems, and ensure holistic care for mothers and children. This paper explores two prominent nursing theories—Meleis' Transition Theory and Mercer’s Maternal Role Attainment Theory—highlighting their theoretical underpinnings, concepts, and clinical applications. Meleis’ Transition Theory provides a comprehensive framework to support individuals undergoing significant life changes, such as illness, parenting, or hospital discharge. It emphasizes the universal nature of transitions, requiring nurses to offer care during critical milestones, fostering healthy coping and adaptive outcomes. The theory underscores the importance of understanding disruptions, critical points, and skill acquisition in navigating transitions, aiming to develop interventions that ensure positive experiences and well-being. In contrast, Mercer’s Maternal Role Attainment Theory focuses specifically on the maternal role, outlining a process of identity development through four stages: commitment and preparation, acquaintance and learning, normalization, and maternal identity achievement. This theory emphasizes the bond between mother and child and the vital role of nursing in facilitating this bond. Key concepts include the maternal self, environmental influences, health, and the integral role of nursing in promoting family well-being through education and support. A clinical scenario involving a rural woman with ten children highlights the application of both theories. Meleis’ Transition Theory guided counselling interventions addressing the couple’s resistance to family planning by leveraging moral and religious grounds. Simultaneously, Mercer’s Maternal Role Attainment Theory supported the mother’s education on neonatal care, maternal health, and family well-being. The comparison revealed that Mercer’s theory offers a more structured approach to addressing maternal health, empowering mothers, and fostering better long-term family outcomes. This comparative analysis underscores the significance of theoretical frameworks in nursing practice, validating the integration of evidence-based approaches to improve maternal and neonatal health. Nurses can enhance caregiving, strengthen family systems, and ensure holistic care for mothers and children by aligning clinical practice with these theories.