Cooperative education (co-op) is a strategy of education that includes a requirement for successful completion of both formal classwork and work placements to gain a qualification. The work placements immerse the student in relevant productive work, and are seen as an integral part of the educational programme. Although there is anecdotal and research data in the literature about the success of co-op programmes, little theorising and research about learning in placements has been published which could help practitioners legitimise their co-op placements as educational, and enhance development of appropriate pedagogy and curricula for co-op programmes. Sociocultural views of learning, that depict learning as a mediated, situated and participatory activity within a socially and culturally determined community of practice, were proposed to address these concerns. This study addressed the lack of theoretical understanding of co-op by investigating, through a sociocultural view of learning lens, what and how a cohort of co-op students learnt through undertaking work placements in science and technology. An interpretive methodology was adopted to probe the students’ experiences within the placements they carried out as part of their BSc(Tech) degree programmes at the University of Waikato. This study found that student learning in co-op work placements can be viewed as a socially mediated, situated and participatory activity. Most learning was achieved by working alongside a practising professional, engaged in authentic activities, as the students gained legitimate access to a new community of practice and became enculturated into ways of thinking and acting as a member of that community. The students learnt through social interactions, and the use of the language and other tools of the community. The students learnt about the practice of science and technology through their participation in science and technology workplaces. They came to understand the nature of the workplace enterprise, and developed specific skills and knowledge that allowed them to feel part of their community. This study has found that student learning in co-op placements can be seen as complementary to university classroom learning. Students felt they could integrate their learning between the two settings when they could apply discrete skills or knowledge from one to the other. Yet, for some students who could see little integration between their placement learning and that of the university classroom, learning in each setting may still complement the other to provide a valuable education. The students noted different learning and assessment modes between the two environments, indicating that they would benefit from a pedagogical and curriculum design in their co-op programme that would help ease the transition between the two. From a sociocultural perspective, these co-op students can be seen as learning within two distinct socially and culturally-determined communities of practice, the university and the workplace. How they are able to make connections between these communities, with the help of the co-op placement coordinator, will determine how they make the transition between student to science and technology practitioner.