The continuously evolving and dynamic social, economic, political environments and public pressures demand governments to deliver effective and efficient public services. In the quest for meeting these demands, governments respond by designing extensive reforms and performance objectives to improve the efficiency and responsiveness of their agencies. Many governments have adopted Business Process Management (BPM) as a strategy to achieve these reforms. However, the successful implementation of BPM initiatives has been a challenging task for agencies responsible for these initiatives, with many projects not reaching completion or not achieving the intended outcomes. This paper reports the results of a systematic literature review on critical success factors (CSFs) related to BPM projects in the public sector. We analysed 31 papers in this review covering both the developed and developing country contexts, sourced from refereed and peer reviewed journals. A quasi-deductive approach was applied for the qualitative data analysis using NVivo 10 software. This resulted in the synthesis and identification of 14 critical success factors of BPM in the public sector, each defined and described in detail with specific attention to the sub-factors mentioned within the literature. Any differences between developed and developing country contexts were sought for, and the observations critically analysed. We propose a series of research questions, designed to support the progression of BPM in the public sector of developed as well as developing countries.