Background: Older adults are vulnerable to infection and infections developing into severe diseases during the COVID-19 pandemic. Performing individual preventive behaviors including hand washing frequently, facemask wearing and physical distancing play an important role to reduce the transmission of COVID-19 in the community. Identifying key correlates of the preventive behaviors that are modifiable through intervention is a recognized priority. This study aimed to examine the association of social-cognitive factors (motivational and volitional factors) with preventive behaviors in a mixed-sample of older adults from China and Germany and to evaluate the moderating effects of countries on the associations of these factors with preventive behaviors.Methods: Cross-sectional questionnaire surveys were conducted in China (June 2020 to July 2020) and Germany (June 2020 to February 2021). 578 older adults completed the online survey (N Chinese = 356, mean age = 67.75, SD = 6.24, 39.6% females; N German = 222, mean age = 69.09, SD = 6.9, 63.5% females). The questionnaire consisted of demographics, three preventive behaviors (hand washing, facemask wearing and physical distancing) before and during the pandemic, motivational factors (health knowledge, attitude, subjective norm, risk perception, motivational self-efficacy, intention) and volitional factors (volitional self-efficacy, planning and self-monitoring) of preventive behaviors. Univariate linear regressions and multiple hierarchical linear regressions with simple slope analyses were used. Results: The majority of motivational and volitional factors were associated with three preventive behaviors with small-to-moderate effect sizes (f2 = .02 to .17), when controlling for demographics and past preventive behaviors. When country was included in the regression models, it predicted all three preventive behaviors. Country also moderated five associations, including 1) volitional self-efficacy and hand washing, 2) self-monitoring and facemask wearing, 3) motivational self-efficacy and physical distancing, 4) volitional self-efficacy and physical distancing, and 5) planning and physical distancing. Conclusions: Findings underline the generic importance of modifiable factors and addressing them through preventive behavior interventions especially increasing health knowledge, developing intentions and plans, and strengthening self-efficacy among older adults. Country-related mechanisms should be considered when aiming to learn from other countries on the promotion of preventive behaviors.