This paper reports on the effectiveness of a professional partnership approach to preparing pre-service primary teachers to teach science. The study involved final year BEd pre-service primary teachers at the University of Tasmania, each working in the class of a volunteer colleague teacher. The programme provided an authentic science teaching experience in which pre-service teachers were supported to plan and teach a sequence of work in a chosen science topic and reflect upon the experience. Many reported an initial lack of confidence in science and no experience with teaching it during their normal practice teaching. During 2007 and 2008, teachers from 17 schools in Northern Tasmania volunteered to work with the pre-service teachers in their classrooms for one lesson a week over a six-week period. The findings indicated that this approach was an effective way to build the confidence of pre-service teachers and may also have benefits for practising teachers. (Contains 3 tables.)