Exploiting regional heterogeneity in population dynamics across more than 10,000 municipalities in Germany, we provide robust empirical evidence that population aging depresses real estate prices and rents. Using millions of individual real estate offers and detailed demographic data on the municipality level, we estimate that average sales prices in 2020 would have been up to 12% higher, if the population age distribution had been the same as in 2008. We show that population aging does not only reduce prices but also increases the availability of real estate. Moreover, we document substantial heterogeneity in price responses by dwelling type, real estate characteristics and urban-rural status which suggest that a lower demand for living space and live-cycle dissaving are driving our results. We predict that population aging will continue to put downward pressure on real estate prices and exacerbate regional disparities in Germany.