Pretraumatic stress has the same symptoms as post-traumatic stress but instead pertains to anticipated threats. There is evidence that pretraumatic stress occurs among soldiers and pregnant people. Objective We analyzed correlates of pretraumatic stress concerning the threat of COVID-19 infection. Method Our pilot study was cross-sectional (N = 74); our main study was longitudinal and consisted of three waves (N = 1067, N = 894, and N = 752 for Waves 1, 2, and 3, respectively). Our pilot study used correlation and multiple linear regression. Our main study used quadratic regression and a random intercept cross-lagged panel model. Results The pilot study found that pretraumatic stress was positively correlated with agreeableness (r = .24, p < .01) and negatively correlated with emotional stability (r = -.30, p < .01) and intellect/imagination (r = -.37, p < .01). The main study demonstrated that pretraumatic stress was positively correlated with other measures of mental health problems during the COVID-19 pandemic and with perceived positive aspects of the pandemic (r = .11, p < .01). There is evidence of a U-shaped relationship between pretraumatic stress and perceived positive aspects of the pandemic. A random intercept cross-lagged panel model analysis demonstrated that pretraumatic stress in Wave 2 was negatively predicted by levels of prosocial behavior in Wave 1 (B = -1.130, p < .01). Conclusion Mental health professionals should take into account pretraumatic stress, not only as a possible consequence of the COVID-19 pandemic outbreak but more generally as a risk in situations that are new, difficult, and challenging for people.