Preface The Clinical Practice Guidelines (CPG) for the Diagnosis and Management of Pediatric Community-Acquired Pneumonia (PCAP) was initiated by the Philippine Academy of Pediatric Pulmonologists, Inc. (PAPP) and the Pediatric Infectious Disease Society of the Philippines (PIDSP), in cooperation with Philippine Pediatric Society, Inc. (PPS) way back in 2004. Several CPG updates were then undertaken by the PAPP PCAP CPG Task Force from 2008 to 2016. Clinically-relevant research questions were answered with recent and current recommendations based on evidence from local and international data. The 2021 PCAP CPG initiative was envisioned in March 2018 upon the recommendations of the 2018 PAPP Board for the purpose of updating the evidence in the PCAP CPG 2016 clinical questions. This led to the collaboration of PAPP and PIDSP to develop this CPG. Individual members were identified from each society as content experts to form the Steering Committee along with a clinical epidemiologist and technical writer as review experts. The committee identified the scope and target end user of the CPG as well as additional clinical questions to be included in the 2021 update aside from the questions on the previous CPGs. Selected members from the two societies formed the Technical Working Group (TWG) who did the literature search, appraisal of evidences, and formulation of recommendations. These recommendations were then presented to the stakeholders who became part of the consensus panel. There was no identified conflict of interest among the CPG developers, TWG members and stakeholders. A survey to determine potential competing interests were conducted during the development of this CPG. This initiative was fully funded by the PAPP and PIDSP societies. The 2021 PCAP CPG significantly differs from the previous CPGs in several aspects. First, the current guideline is a consensus between two pediatric societies. Second, much of the literature review has been centered on meta-analyses or systematic reviews instead of individual studies. Finally, appraisal of published literature was based on Grading of Recommendations, Assessment, Development and Evaluation (GRADE) criteria. Such methodological differences may provide difficulties in defining evolution of care through the years. As identified in the previous CPG updates, there is lack of local data hence most of the evidences gathered came from international studies. The applicability of such data to the local setting needs to be critically assessed for its value and relevance. Corollary to this, several gaps in knowledge are identified and these may serve as a guide for future research.