New technologies now offer teachers alternative models of collaboration with schools overseas, but how effective are they as professional development opportunities? The experiences of 18 specialist primary and secondary teachers in the Teachers' International Professional Development Programme who visited schools in the USA were investigated as they set about establishing collaborative projects with their hosts. The focus was on the potential of such collaboration to engender professional development outcomes and to investigate the circumstances enabling or impeding success. Data were collected by means of questionnaires and interviews, both during the visit and for 20 months after return. A surprising result was the small number of teachers who managed to start a collaborative project. One of the more frequently cited reasons for lack of progress was technical problems, and this was with a group of teachers who were information and communications technology specialists. Other inhibitory factors were lack of time and lack of funding. However, additional examination reveals other benefits arising from the exercise (e.g., in terms of professional development of a broader kind), including a range of factors that could maximize the success of future projects.