There has been a noticeable variance between countries in the growth rate of COVID-19 since the start of the pandemic. Researchers attempted to understand this variance from two primary perspectives: the policies implemented to curb the spread of the virus [1] and the cross-country cultural differences [2]. However, little research to date has looked at the joint effects of policy responses and national culture. We argue that the effectiveness of restrictive policies depends on cultural values. Specifically, when policies are non-mandatary, cultural values influence people's voluntary adherence to these policies, and hence, the spread of COVID-19. We analyzed the growth data in daily new cases across 78 countries, focusing on the joint impact of containment policies and cultural values. We found that although policy responses (i.e., containment policies) significantly predicted the spread rate of COVID-19 over time, their effects were moderated by cultural variables as well. Implications for policymaking are discussed.