Public procurement capacity is composed of three facets: individual; organizational; and an enabling national environment which encapsulates national legislation, policies, and institutional arrangements that can facilitate or hamper the effectiveness of procurement. This study investigated the extent to which procurement capacity challenges in the national environment affect the effectiveness of infrastructure procurement by public agencies in Nigeria. Design/methodology/approach: 30 procurement capacity challenges drawn from literature were operationalized in a survey of infrastructure procurement personnel in different tiers of public agencies (i.e. local and state government) in order to ascertain the critical challenges affecting the effectiveness of infrastructure procurement. The survey yielded 288 responses, which were analysed using descriptive statistics, one sample ttest and independent samples t-test. Findings: Challenges related to transparency, integrity and accountability are amongst the topmost challenges adversely affecting the effectiveness of public infrastructure procurement. There is limited difference in the extent to which the challenges affect the effectiveness of infrastructure procurement in different tiers of public agencies in Nigeria. Originality/value: Whilst various procurement capacity challenges have been identified in the extent literature, this study has shown that an assessment of their effect on the effectiveness of infrastructure procurement could reveal valuable insights regarding the status of public infrastructure procurement within a country, particularly countries in sub-Saharan Africa and other developing regions where there is acute infrastructure deficits. Such insights could inform appropriate infrastructure procurement reforms by policy makers, procurement entities, and infrastructure funders.