Companies’ ability to learn from projects is a source of competitive advantage in project-based industries. Learning from experiences in international markets is particularly important for global contractors so that the right bidding strategy can be developed, effective project governance systems can be established, and similar mistakes are not repeated. In this study, we assert that countries can be clustered according to their similarity so that experiences gained in these markets can be transferred and adapted to forthcoming projects. Thus, similarity factors to be used for clustering of countries can be identified, and a methodology can be developed to store, retrieve and reuse country-related information in international construction projects. In this paper, we report the factors identified for similarity assessment of countries to be used to facilitate learning from projects. As a result of literature review, interviews with experts and an online questionnaire administered to company professionals who have international construction experience, 12 factors have been identified for clustering of countries. As a result of ranking analysis; factors of “development level of and culture in the construction industry”, “political condition of the country” and “financial condition of the country” are obtained as the most important factors. The identified factors will be explained and how the clustering of countries can help companies to extract valuable information from previous experiences will be discussed.