In 2018 global leaders renewed their political commitment to primary healthcare (PHC) ratifying the Declaration of Astana emphasising the importance of building a sustainable PHC system based on accessible and affordable delivery models strengthened by community empowerment. Yet, PHC often remains underfunded, of poor quality, unreliable and not accountable to users which further deprives PHC of funding. This paper analyses the determinants of PHC expenditure in 102 countries, and quantitatively tests the influence of a set of economic, social and political determinants of government expenditure on PHC. The analysis is focused on the determinants of PHC funding from government sources as the government is in a position to make decisions in relation to this expenditure as opposed to out-of-pocket spending which is not in their direct control. Multivariate regression analysis was done to determine statistically significant predictors.Our analysis found that some economic factors-namely Gross Domestic Product (GDP) per capita, government commitment to health and tax revenue raising capacity-were strongly associated with per capita government spending on PHC. We also found that control of corruption was strongly associated with the level of total spending on PHC, while voice and accountability were positively associated with greater government commitment to PHC as measured by government spending on PHC as a share of total government health spending.Our analysis takes a step towards understanding of the drivers of PHC expenditure beyond the level of national income. Some of these drivers may be beyond the remit of health policy decision makers and relate to broader governance arrangements and political forces in societies. Thus, efforts to prioritise PHC in the health agenda and increase PHC expenditure should recognise the constraints within the political landscapes and engage with a wide range of actors who influence decisions affecting the health sector.