Background: In India, birth defects, nutritional deficiencies, disabilities, and developmental delays among children cause significant public health challenges. The Ministry of Health and Family Welfare, aims to address these issues through the Rashtriya Bal Swasthya Karyakram (RBSK) program. RBSK nurses are the crucial part of this program. They screen the children between zero to eighteen years as a part of early intervention. This study mainly aimed to map the competencies among RBSK nurses from randomly selected districts of Kerala. Methods: This qualitative study employed key informant interviews with the state nodal officer, district early intervention centre managers, and district coordinators; and in-depth interviews (IDIs) with RBSK nurses, as well as report and document review. Inductive coding was applied to two selected interview transcripts from each district, followed by deductive coding with the rest of the transcribed data to derive themes. Results: The findings are presented using the ‘core competencies of public health professionals’ as revised and adopted by the council on linkages between academia and public health practice in 2021. RBSK nurses in Kerala exhibited proficiency in multiple domains, including knowledge of child health issues, clinical skills, communication, patient education, care for vulnerable population, organizing activities, electronic health record usage, multitasking, teamwork, and problem-solving skills. Conclusions: This dedication and proficiency demonstrated by RBSK nurses in Kerala, serve as a global model for emphasising the importance of early intervention and comprehensive care for children.