PurposeThe purpose of this study is to investigate the influence of knowledge management critical success factors (KM CSFs) on project management performance outcomes in major construction organisations in Sri Lanka. As a result, the significant KM CSFs are prioritised to support KM implementation.Design/methodology/approachThis study is cross-sectional in nature, adopting the quantitative method of analysis. The research model includes nine KM CSFs (culture, leadership, organisational structure, IT support, T-shaped skills, training, teamwork, performance measurement and benchmarking) and nine items measuring project management performance outcomes. Data were collected from senior, middle and technical staff involved in projects by means of a self-administered survey questionnaire mailed to them.FindingsThe Pearson’s correlation coefficient suggests that all of the KM CSFs are adequately correlated except for organisational structure, which has a poor correlation with IT support, T-shaped skills, teamwork and benchmarking. The results of multiple linear regression show that four KM CSFs (T-shaped skills, teamwork, benchmarking and transformational leadership) are significantly and positively related to project management performance outcomes. The remaining five KM CSFs are not significant. The multiple-criteria decision-making analysis reveals that benchmarking, transformational leadership, teamwork and T-shaped skills are the main priority for the construction organisations to consider in implementing KM.Research limitations/implicationsFuture studies should consider construction organisations of multiple sizes and include factors beyond organisational control, KM processes and the effects of demographic variables. Longitudinal studies are also imperative to determine the performance impact brought about by KM implementation over a period of time.Practical/implicationsBenchmarking, transformational leadership, teamwork and T-shaped skills should serve as the initial focus to support KM implementation to achieve the desired project management performance outcomes. It is only after these KM CSFs are in place that the construction organisations can concentrate on other factors.Originality/valueThis study contributes to a better understanding of the relationships between the KM CSFs and project management performance outcomes in the construction industry in Sri Lanka, which is still at its infancy stage of KM implementation. Prioritisation of the significant KM CSFs in supporting effective KM implementation in the construction organisations further enhances the value of this study.