There has been much recent interest in the extent to which the teaching in higher education delivered by non-academic staff has increased in the recent past. Within the Biosciences there has always been a tradition of engaging postgraduate students to support the delivery of some forms of teaching. In this paper we report on the findings of a survey of bioscience departments in the UK to explore the delivery of teaching by graduate teaching assistants (GTAs). A key finding is that there does not appear to have been a significant increase in the amount of teaching delivered by GTAs: only 18% of responding departments reported an increase in the use of GTAs over the last five years. The most common form of employment of GTAs is in supporting the delivery of practical classes, particularly in year 1, though GTAs are engaged to varying extents in all forms of teaching. All of the institutions that responded indicated that some forms of training were provided, though this varied in range and in perceived quality. Overall, the academic staff indicated general satisfaction with the quality of the teaching undertaken by GTAs. (Contains 1 table and 4 figures.)