ObjectiveTo explore regional primary care improvement strategies that are potentially determinants of primary care performance.DesignMultiple comparative embedded case study.SettingThree regions in Canada: Fraser East, British Columbia; Eastern Ontario Health Unit, Ontario; Central Zone, Nova Scotia.Data sources(1) In-depth interviews with purposively selected key informants (eg, primary care decision-makers, physician leads, regulatory agencies) and focus groups with patients and clinicians (n=68 participants) and (2) published and grey literature (n=205 documents).Outcome measuresVariations in spread and uptake of primary care improvement strategies across the three study regions. NVivo (V.11) was used to manage data and perform content analysis to identify categories within and across cases. The coding structure was developed by researchers through iterative collaboration, using inductive and deductive processes.ResultsSix overarching primary care improvement strategies, differing in focus and spread, were implemented across the three study regions: interprofessional team-based approaches, provider skill mix expansion, physician groups and networks, information systems, remuneration and performance measurement and reporting infrastructure.ConclusionThe addition of information on regional improvement strategies to primary care performance reports could add important contextual insights into primary care performance results. This could help identify possible drivers of reported performance outcomes and levers for change in practice, regional and system-level settings.