The quest for Critical Success Factors “CSF” in project management in every industry is the aim of company and project manager around the world. This is primarily because of the cost attached to such large-scale projects, especially those financed by governmental entities, municipalities and provinces. Large-scale construction projects in particular have a critical impact on governmental budgets, economic growth, and ecology. As such, determining what critical success factors that directly contribute to cost reduction, timely delivery, improvements in quality of construction and positive impact on the environment can being mutually beneficial to all participants and stakeholders. The state of Oman like other GCC countries has a particular interest in determining such CSF in the post financial crises, where numerous landmark projects has been frozen due to financial constraints. Therefore, avoiding pitfalls in project management related factors could significantly impact the future role of British and Western construction companies in the Gulf and other parts of the world in post-Brexit U.K. The pressure on British companies is equally higher today than ever before to maximize the effectiveness in implementation of construction related projects internationally, to compete with other European and Chines construction firms. Innovation and cultural forces are found to play a significant role in cross-cultural project success. Such forces then can be viewed in relation to CSF will ultimately affect all participants and beneficiaries, stakeholders and the environment. Therefore, the attempt to explore varying CSF is more important to governments in developing economies, and private sectors involved in future construction projects, as much as it is important to Western firms attempting to compete and expand their market base in such critical part of the world and uncertain outlooks for the U.K. economy particularly.