Purpose – Typically, organizations tumble with project management, and failure rates are high. Usually, one key factor in establishing a manageable and successful project portfolio is to take into account interdependencies between different projects (resources, technology and market). With an increasing amount of international cross‐border project activity, it is vital to know how different countries manage interdependencies, and how management practices differ between countries. Design/methodology/approach – This research bases its empirical findings on a large‐scale questionnaire completed during 2007‐2008 in Estonia and Finland. Altogether, 288 responses were gained, and roughly two‐thirds of the answers originated from Finland and one‐thirds from Estonia. Respondents were industrial and service companies. Findings – The results of the survey indicate similarities and some significant differences between Estonian and Finnish responses. Some country size and context‐dependent hypotheses were not supported or only weakly supported, indicating great homogeneity between managerial issues of interdependency internationally. However, existing significant differences may stem from historical and cultural reasons, such as, peculiarities of transition country compared to mature country. Research limitations/implications – The main limitation arises from the analyzed sample, which was mostly limited to information and communication technologies, engineering, machinery and construction industries and thus the findings may not be directly applicable to other industries. Because responses originate only from two Finno‐Ugrian countries, this limits the generalizability of the research results directly into other regions and countries. Practical implications – Managing interdependencies between projects has a clear practical significance, and it appears in companies in both of the countries in the form of bringing additional value, saving costs and in increasing the success rate of projects. In addition, international project owners can find differences in their daily work. Originality/value – This research provides empirical evidence for the less investigated, but emerging field of interdependency phenomenon of project management. To the authors' knowledge, no research to date concerns cross‐country comparison.
