There is a growing interest in public-private partnerships (PPPs) as a model for e-government service development and delivery. Although various underlying benefits of such arrangement have been enumerated, there exist challenges and issues in PPPs manifest in a number of unsuccessful cases. The success of PPPs in e-government depends on a number of factors that need to be considered from the first stage of evaluating the PPP to the last stage of development and roll-out. However, there is a dearth of PPP studies in the e-government literature that identified the success factors behind these efforts. Hence, this research attempts to address the existing gap by investigating what factors contribute to a successful e-government PPP. The paper starts out by introducing the relevant concepts and literature and then providing a review of e-government PPPs in Singapore, which has been a leader in e-government. We identify success factors based on existing studies and information of 5 cases of e-government PPPs. In future, we plan to collect data from new cases to further develop and validate these factors and identify their inter-relationships. This study is expected to contribute to research and practice by identifying success factors in different stages of e-government PPP.