Collaborative testing has been shown to enhance student performance compared to individual testing. It is suggested that collaborative testing promotes higher order thinking, but research has yet to explore this assumption directly. The aim of this study was to explore the benefits of collaborative testing on overall performance, as well as performance on higher order thinking questions. It was hypothesised that, compared to individual test results, students would perform better overall and on higher order thinking questions under collaborative testing conditions. It was expected that these differences would be equal when comparing students of different academic abilities (i.e. 'upper', 'middle' and 'lower' performers). Undergraduate students completed an individual followed by a collaborative test as part of summative assessment. Analyses revealed that with the exception of upper performers, students performed better overall on the collaborative test. Additionally, regardless of their academic abilities, students performed better on the higher order thinking questions under collaborative conditions. This improvement was equal across different academic abilities, suggesting that collaborative testing promotes higher order thinking even when taking into account previous academic achievement. The acceptability and application of collaborative testing is discussed.