To identify and prioritize the needs for new research evidence for primary health care (PHC) in low-and middle-income countries (LMICs) about organization, models of care, and financing of PHC. Three-round expert panel consultation of LMIC PHC practitioners and academics sampled from global networks, via web-based surveys. Iterative literature review conducted in parallel. Round 1 (pre-Delphi survey) elicited possible research questions to address knowledge gaps about organization and models of care and about financing. Round 2 invited panelists to rate the importance of each question, and in round 3 panelists provided priority ranking. One hundred forty-one practitioners and academics from 50 LMICs from all global regions participated and identified 744 knowledge gaps critical to improving PHC organization and 479 for financing. Four priority areas emerged: effective transition of primary and secondary services, horizontal integration within a multidisciplinary team and intersectoral referral, integration of private and public sectors, and ways to support successfully functioning PHC professionals. Financial evidence priorities were mechanisms to drive investment into PHC, redress inequities, increase service quality, and determine the minimum necessary budget for good PHC. This novel approach toward PHC needs in LMICs, informed by local academics and professionals, created an expansive and prioritized list of critical knowledge gaps in PHC organization and financing. It resulted in research questions, offering valuable guidance to global supporters of primary care evaluation and implementation. Its source and context specificity, informed by LMIC practitioners and academics, should increase the likelihood of local relevance and eventual success in implementing research findings.