This paper presents findings from a small-scale research study eliciting students' perceptions of benefits and challenges of working in interdisciplinary groups to solve an engineering challenge using problem-based learning. Penultimate and final year undergraduates and postgraduate MSc students in the School of Engineering and Physical Sciences at a Scottish university, studying Robotics, Mechanical, Chemical, Electrical and Software Engineering worked in interdisciplinary groups of five on a project to provide solutions to the United States National Academy of Engineering Grand Challenges (NAEGC). Students were surveyed twice, using closed and open questions before and towards the end of the project. Data were analysed using a thematic approach. Findings showed that most students saw benefits to problem-based working with students from other disciplines, citing increased awareness of approaches, future 'real world' professional preparation and efficiency in problem solving. However, challenges around scheduling meetings and concerns around cross-discipline collaboration indicate that universities should provide training for students before undertaking such problem-based projects, to ensure maximum educational benefits. In addition, greater emphasis needs to be put on students' awareness of the added benefits of development of the 'soft skills' needed for future professional practice.