AbstractBoth the increase in traveler numbers and the heightened threat posed by terrorism in recent years represent significant challenges to airport security measures. To ensure that a high level of security is maintained, randomized security checks have been proposed as a promising alternative to traditional security approaches. The use of randomized checks means that only a specific number of people are selected for security screening. However, the likely effects of such a change in security procedures on travelers’ security perceptions and on the deterrence of criminal activities remain unclear. Thus, the present study examines how varying the percentage of people screened during security checks influences people's security perceptions. In two online experiments, the participants were asked to imagine that they sought to smuggle an explosive dummy past an airport security check. The only information provided was the number of people screened during security checks, which was manipulated between‐subjects in the first experiment and within‐subjects in the second experiment. The participants then had to rate their security perception (i.e., the perceived likelihood of successfully smuggling the explosive dummy). The findings show that people perceive traditional security checks to be safer than randomized checks, irrespective of whether 90% or 30% of people are screened. Hence, if randomized security checks would indeed be implemented, it would automatically lead to a decreased perception of security. Furthermore, this decreased security perception might lead to an actual reduction in security, as the deterrence of criminal activities could also be reduced.