Despite increasing recognition for the importance of interprofessional education (IPE), little is known about where in the world it occurs, how it is conducted and why it is offered. This international environmental scan was commissioned by the World Health Organization (WHO) to answer these questions and inform efforts to support IPE on a global scale. An internet-based survey targeting educators and researchers in WHO's 193 Member States was conducted between February and April 2008. Participants were recruited by WHO staff through a range of country focal points, collaborating centres, regional networks and partner organizations. The scan garnered 396 responses representing 41 countries from WHO's six regions, various income-economies and many health professions. IPE was often (i) voluntary (22%); (ii) not based on explicit learning outcomes (34%); (iii) not assessed for what was learned (63%); (iv) not offered by trained facilitators (69%); and (v) not formally evaluated (30%). Participants reported many benefits of IPE for education, practice and policy. Results are limited primarily by reliance on self-reports and an English-only, internet-based questionnaire. Significant efforts are required to ensure that IPE is designed, delivered and evaluated in keeping with internationally recognized best practice.