Introduction: The integration of infant and young child feeding into childcare settings is important to the overall wellbeing of a community. To our knowledge, there is no questionnaire at the national context specifically on the knowledge, attitude and practice (KAP) of infant and young child feeding among childcare providers. Preexisting questionnaires are unsatisfactory due to different target populations and validation approaches. This study aims to develop a new questionnaire for assessing the KAP regarding infant and young child feeding among childcare providers in Malaysia. Methods: A new questionnaire on childcare providers’ KAP was developed using literature review, expert opinions, and a theoretical framework. It was developed using a modified Delphi technique in five phases: 1. Identification of the domains, 2. Verification of the identified domains, 3. Definition of the domains, 4. Identification of relevant and representative items for each domain, and 5. Final verification of the domains and items, followed by a pre-survey evaluation. Results: The final items were verified by experts with references to relevant literatures, other questionnaires, and experts’ experiences. A total of 236 items were selected after consideration of their relevancy and representativeness: 104, 90, 42 items addressing knowledge, attitude, and practice, respectively. The questionnaire was named Borang Kaji Selidik Pemakanan Bayi dan Kanak-kanak dalam kalangan Pengasuh, or IYCFCCPQ. Conclusion: The IYCF-CCPQ is a newly developed questionnaire to measure childcare providers’ KAP regarding infant and young child feeding.