In many traditional types of translator training, there is a strong focus on individual work undertaken by trainee translators, while pair work and group work is used less extensively. Such a focus may, to some extent, reflect the contemporary Western perception of translation as a solitary activity, with a single translator working individually, isolated from the rest of the world. This perception, however, is oversimplified since translation often involves some type of collaboration, such as the translator collaborating with an editor, a copyeditor, the client or a disciplinary expert. In addition, some of the emerging trends in translation in the digital age are collaborative in their nature (e.g. crowdsourcing). It seems therefore that collaboration is an aspect of translation that needs to be addressed more carefully in translator training. The present paper reports on a study focusing on collaboration in a translation course. The goal of the study was to examine the types of collaboration that trainee translators use when they are presented with a collaborative assignment. In the study, trainee translators were asked to complete two collaborative translation assignments using a wiki, which enables monitoring the degree of participation for each wiki participant. The first assignment encouraged free collaboration in an attempt to mirror informal collaboration that trainee translators resort to occasionally: trainee translators were asked to collaborate in any way they wished. The second assignment was focused on structured collaboration: trainee translators were given detailed guidelines on the types of collaboration expected of them, and on the extent of the contribution they were expected to make. The findings show that the second assignment resulted in more intensive teamwork and promoted more diverse types of collaboration than the first assignment. This suggests that carefully structured collaboration should be given additional attention within the context of translator training.