PurposeDrawing on the third-person effect (TPE) theory and the theory of planned behavior (TPB) as a theoretical framework, the current study aims to explore the cognitive mechanisms behind how third-person perception (TPP) of misinformation about public health emergencies affects intention to engage in corrective actions via attitude, subjective norms and perceived behavioral control.Design/methodology/approachA total of 1,063 participants in China were recruited via a professional survey company (Sojump) to complete an online national survey during the outbreak of coronavirus (COVID-19) in China. Structural equation modeling using Mplus 7.0 was used to address the research hypotheses.FindingsThe results reveal that attention to online information about public health emergencies significantly predicted TPP. In addition, TPP positively influenced attitude and perceived behavioral control, which, in turn, positively encouraged individuals to take corrective actions to debunk online misinformation. However, TPP did not significantly influence subjective norms. A potential explanation is provided in the discussion section.Research limitations/implicationsThe research extends the TPE theory by providing empirical evidence for corrective actions and uncovers the underlying cognitive mechanism behind the TPE by exploring key variables of the TPB as mediating constructs. These are all significant theoretical contributions to the TPE and offer practical contributions to combating online misinformation.Originality/valueThe research extends the TPE theory by providing empirical evidence for a novel behavioral outcome (i.e. corrective actions in response to misinformation) and uncovers the cognitive mechanism underlying the TPE by exploring key variables of the TPB as mediating constructs. These are all significant theoretical contributions to the TPE and offer practical contributions to combating online misinformation.