Introduction: International travel for organ transplantation (ITOT) may involve ethically legitimate transplants as well as organ trafficking or transplantation that undermines self-sufficiency in destination countries (“transplant tourism”). The proportion of worldwide solid organ transplants suspected to involve organ trafficking or transplant tourism, is regularly cited as 5-10%. However, this figure is more a rule of thumb than an evidence-based estimate. There are also limited data about ITOT in general, including data about ethically appropriate activities.

Method: Drawing on the peer reviewed literature, the aim of this study is to explore the range of current mechanisms used to collect and report data about ITOT. We examined current examples of donation and transplantation registries at national, regional and global levels. We discuss the strengths and limitations of each approach, as well as potential barriers to routine reporting to enable better quantification of ITOT.

Results: Review of the literature has demonstrated there are several factors that undermine efforts to quantify ITOT and organ trafficking even at the country level. The most important of these may be the obscuration of trafficking activities under cover of legally authorised transplants approved by ethics committees. Although there are also barriers to collection and reporting of data about legitimate ITOT, these data are increasingly available in national and international transplant registries. However, the analysis and comparison of data from different registries may be difficult in the absence of harmonization.

Conclusion: Systematic data collection and reporting of ITOT are essential for efforts to address organ trafficking, support self-sufficiency and to assist patients seeking care abroad. Mechanisms to facilitate reporting and harmonization of registry data are urgently needed.