There has been a dramatic growth of individuals using online auctions especially within Consumer-to-Consumer (C2C) e-commerce coupled with increasing academic attention to behaviour in the online environments. Literature has identified the influence of attitudes, perceptions, trust and security on individual’s online auction transaction intentions and behaviours. The aim of this study, therefore, was to predict and understand individuals online auction transaction intentions and behaviours through the application of the Theory of Planned Behaviour (TPB). Three hundred and seventy-two respondents completed the survey within two geographical regions. Findings reported that attitudes, self-efficacy and trust significantly influenced intentions; while intentions and self-efficacy significantly influenced online auction behaviours. Interestingly, social pressures, perceived control and security failed to have any influence. Overall, the study provided greater insight into which salient drivers influence transaction behaviours and intentions.