Purpose: The purpose of this paper is to provide a brief overview from the literature on how best to define megaprojects in contemporary contexts. There is a need for a definition that encompasses a complex matrix of characteristics, inclusive of positive and negative aspects, which are not necessarily industry or sector specific. Whilst megaprojects have often been described and defined in terms of cost, they are more accurately delineated by their convolutions. Intricacies arise from political intrigues surrounding funding of such projects and managing and governing complex social and organizational relations. Points for future research are also identified. Design/methodology/approach: An analysis of international megaproject literature over the past five years combined with seminal works was undertaken, drawing on the broad literature of project and program management combined with elements of organizational theory. Whilst some examples are cited, in-depth case analysis has not been covered. Findings: Albeit that the scale of some megaprojects is comparable to national GDPs, seven more characteristics beyond size have been identified, which distinguish megaprojects from large projects. These include: reach; duration; risks and uncertainties; widely disparate actors; areas of controversy such as dispute resolution; and legal and regulatory issues. Research limitations/implications: The paper takes a broad overview and whilst some examples are cited, in-depth case analysis has not been covered. The overview does however provide a good synopsis of the future research areas that warrant exploration. Practical implications: The paper identifies a range of analytical areas for major future research including further exploration of institutional analysis. Areas for further analysis include stakeholder issues; collaboration and understanding between technical and business personnel and reforming notions of procurement and contractual arrangements. Social implications: Rigorous stakeholder engagement is critical for success in megaprojects, and collaborative learnings need to be exchanged. The longer term social and economic impacts need to be viewed as an imperative rather than a hindrance to the planning and execution of megaprojects and complexity rather than cost more aptly defines megaprojects. Originality/value: The paper moves the definition of megaprojects to beyond measurement on the basis of cost to complexity and social and economic variables.