Adoption of protective behaviours is a significant intervention to deal with the current COVID-19 outbreak, even if we get a cure. This study aimed to investigate the effect of risk perceptions, fear and myths about COVID-19 infection susceptibility on protective behaviors in the Pakistani population. An online survey was conducted in Pakistan with a sample size of N=440. A questionnaire was administered in the Urdu language about people’s perceptions of risk, fear, myths, and protective behaviors about COVID-19 infection. Results revealed that perceptions of risk about COVID-19 infection susceptibility had a significant positive effect on protective behaviours. Fear about COVID-19 was significantly correlated with protective behaviors but was not a significant predictor of protective behaviors. Myths about COVID-19 infection were not a significant correlate of protective behaviors. The present sample was found optimistically biased about the susceptibility for COVID-19 infection. Surprisingly, this study provided significant evidence about the adaptive nature of optimistic bias because optimistic estimates about COVID-19 infection susceptibility were significantly predicting protective behaviors. Further studies are suggested to investigate the adoptive nature of optimistic bias related to COVID-19 infection susceptibility.