Preparing engineering students for interdisciplinary practice in the workplace requires a meaningful understanding of interdisciplinary learning in engineering practice. Such an understanding could help to address the ongoing issues and concerns of the interdisciplinary learning of engineering students. The review of literature on interdisciplinary engineering education raises a major concern of the speculative approach to formulating learning outcomes of interdisciplinary engineering education, which results from the lack of understanding of how practising engineers engage in interdisciplinary learning in their workplaces. This thesis directly addresses this concern by providing the empirical evidence for a number of learning outcomes, and by identifying the associated learning practices found in three cases of interdisciplinary collaborations between engineers and life science practitioners. It also enhances the understanding of interdisciplinary learning in engineering practice by providing a detailed explanation of why engineers are more likely to engage in those learning practices and how they are more likely to achieve the learning outcomes. The main contribution of this thesis is in assembling the identified learning outcomes and the associated learning practices into one theoretical framework that embodies both the description and the explanation of interdisciplinary learning in engineering practice for a particular subclass – engineering for the life sciences. The framework describes interdisciplinary learning in terms of four epistemic practices and four learning outcomes. Additionally, it includes a contingent causal explanation for those practices and outcomes by validating the underlying causal relationships. The findings of this research could inform the formulation of learning outcomes and the deployment of learning practices in interdisciplinary engineering curricular. In addition, the generalisation of the findings to the education domain suggests practices that can help university students in their intellectual development.