This study reports on students' and lecturers' perceptions of using wikis as a platform for conducting assessed group projects in two postgraduate Master's level university courses. The results highlight the fact that student attitudes to group work, in general, are mixed, and that the use of wikis "per se" is not enough to improve these attitudes. On the positive side, students found wikis useful for arranging information and sharing knowledge, while instructors thought wikis made managing and marking group work easier and more effective. Other issues related to using wikis as a collaborative learning tool in higher education are also considered.