This article investigates the effects of security threats, namely terrorism, crime, and corruption, on international tourist flows. We estimate a gravity model to evaluate differences in the instability measures between country pairs quantifying not only how security threats in the host country have a negative effect on inbound tourism but also how conditions in the origin country also determine tourism flows to a particular destination. Results show that tourists prefer traveling to countries with similar levels of safety and security as exist in their origin country. Moreover, an asymmetric effect has been found. That is, tourists from stable countries prefer traveling to countries with the same conditions, while tourists from unstable countries are more tolerant with insecurity at the destination country. Finally, we find that greater knowledge about the destination country reduces the negative effect of security threats on inbound tourism.