We find that the foreign-born, who make up about 35 percent of the adult population in California, constitute only about 17 percent of the adult prison population. Thus, immigrants are underrepresented in California prisons compared to their representation in the overall population. In fact, U.S.-born adult men are incarcerated at a rate over two-and-a-half times greater than that of foreign-born men. The difference only grows when we expand our investigation. When we consider all institutionalization (not only prisons but also jails, halfway houses, and the like) and focus on the population that is most likely to be in institutions because of criminal activity (men ages 18–40), we find that, in California, U.S.-born men have an institutionalization rate that is 10 times higher than that of foreign-born men (4.2% vs. 0.42%). And when we compare foreign-born men to U.S.-born men with similar age and education levels, these differences become even greater.