We estimate the effect of a sudden increase in the inflow of refugees on the native population’s mental health in Germany and Swiss. To identify the effect of the sudden influx of refugees to Germany and Swiss, we exploit the quasi-random allocation of the number of refugees to counties in Germany and Swiss. For Germany, we make use of the Socio-Economic Panel. For Swiss, we use individual level data of a large health insurance. Our preliminary results indicate that the sudden increase in the number of refugees increases the individuals’ worries about immigration to Germany but does not change the native population’s mental health in Germany or Swiss.