As the value of multi-disciplinary working in the business and research worlds is becoming more recognised, the number of inter-disciplinary postgraduate environmental and health sciences courses is also increasing. Equally, the popularity of problem-based learning (PBL) is expected to grow and influence instructional approaches in many disciplines. However, very limited research has been conducted to explore the perception of students of PBL in inter- or multi-disciplinary environments; particularly wide-ranging multi-disciplinary courses which cross the natural-social science barrier. The findings from this case study evidence the difficulties and benefits students derive from group PBL, many of which stem from working in multi-disciplinary and multiskilled groups on a part-time basis. Acknowledging, accepting and overcoming conflicts based upon prior experience that influences epistemological and ontological beliefs may be key to the development of effective PBL in inter-disciplinary and  multi-disciplinary programmes. Recommendations for good pedagogic practice to maximise learning in postgraduate environmental and science education are made.