To compare the associations of COVID-19 preventive behaviours and depressive and anxiety symptoms with eHealth literacy and COVID-19 knowledge among Korean adults.

A cross-sectional online survey was conducted in April 2020.

Seoul metropolitan area in South Korea.

1057 Korean adults were recruited.

Associations between eHealth literacy, COVID-19 knowledge, COVID-19 preventive behaviours and psychological distress were computed using Pearson’s correlation and logistic regression analyses. eHealth literacy, COVID-19 knowledge, COVID-19 preventive behaviours and psychological distress were weighted by sex and age distribution of the general population in Seoul Metropolitan area.

68.40% (n=723) perceived high eHealth literacy level (eHEALS ≥26), while 57.43% (n=605) had high levels of COVID-19 knowledge (score ≥25). No significant association between eHealth literacy and COVID-19 knowledge was identified (r=0.05, p=0.09). eHealth literacy and COVID-19 knowledge were significantly associated with COVID-19 preventive behaviours (aOR=1.99, 95% CI 1.51 to 2.62 L; aOR=1.81, 95% CI 1.40 to 2.34, respectively). High eHealth literacy was significantly associated with anxiety symptom (aOR=1.71, 95% CI 1.18 to 2.47) and depressive symptom (aOR=1.69, 95% CI 1.24 to 2.30). COVID-19 knowledge had negative and no associations with the symptoms (aOR=0.62, 95% CI 0.46 to 0.86; aOR=0.79, 95% CI 0.60 to 1.03, respectively). High eHealth literacy with low COVID-19 knowledge was positively and significantly associated with COVID-19 preventive behaviours (aOR=2.30, 95% CI 1.52 to 3.43), and anxiety (aOR=1.81, 95% CI 1.09 to 3.01) and depressive symptoms (aOR=2.24, 95% CI 1.41 to 3.55). High eHealth literacy with high COVID-19 knowledge were significantly associated with more preventive behaviours (aOR=3.66, 95% CI 2.47 to 5.42) but no significant associations with anxiety and depressive symptoms.

We identified that eHealth literacy and COVID-19 knowledge were not associated each other, and differently associated with individuals’ COVID-19 preventive behaviours and psychological well-being. Public health strategies should pay attention to enhancing both eHealth literacy and COVID-19 knowledge levels in the public to maximise their COVID-19 preventive behaviours and mitigate their psychological distress during COVID-19 pandemic.