When considering implementing integrated curriculum models, such as problem-based learning (PBL), concerns may be expressed about the need for increased staff resources required to deliver tutor-led small group PBL. Less staff intensive ways of supporting PBL need to be explored. We compared the outcomes of a PBL module conducted in a large class format within a lecture theatre with a module having the same defined learning outcomes delivered in small group PBL format, both supported by e-learning resources. The pre-existing 27 small groups within the whole class (n = 246) of first year students undertaking a cardiovascular basic science module at Sheffield undergraduate medical school, UK, were randomized to 22 groups undertaking the large class Integrated Learning Activity (ILA) and 5 groups to traditional small group facilitated PBL sessions. Outcome measures were: a pre-post knowledge based test, a student educational effectiveness questionnaire, and assessment of student group work and presentations. There seemed to be no significant differences in learning outcomes between the methods although it is recognized that students would prefer the small group teaching format. Within institutions where resources to support small group PBL are limited, the large group ILA format supported with e-learning techniques may be a useful alternative approach.