This article examines the impact of secret police organizations on the occurrence of antiregime protests in authoritarian regimes. We argue that such organizations are related to lower levels of protests via two related mechanisms: intelligence gathering and an increased perception of risk among citizens, which reduce citizens’ ability and willingness to mobilize, respectively. Using new data on secret police organizations in dictatorships covering the post–World War II period, our findings support the main expectation. This research contributes to our understanding of security institutions, antiregime protests, and the repression-dissent nexus.