Is successful implementation enough? Using Hiltz & Johnson’s (1989) definition of successful implementation, as adoption or acceptance, we discuss the evaluation of a 3D multi-user virtual laboratory for the teaching of radiopharmacy. The views and experiences of educators and learners in Canada and Europe are gathered. Multiple users can enter the virtual laboratory, move an avatar around and communicate with each other while interacting with the virtual world and associated interactive learning resources. Qualitative and quantitative data gathered from three studies suggests that learning effectiveness, satisfaction and acceptance of the virtual laboratory are extremely high in Canada where most learners experienced a sense of presence and became quickly immersed, and where instructor acceptance is extremely high, however, European educators revealed concerns over adoption. We conclude that successful implementation requires not only good participatory design and successful implementation, but also support for educators in integrating it into their teaching practice.