This paper studies the effects of immigration on health. We merge information on individual characteristics from the German Socio-Economic Panel with detailed local labor market characteristics for the period 1984 to 2009. We exploit the longitudinal component of the data to analyze how immigration affects the health of both immigrants and natives over time. Immigrants are shown to be healthier than natives upon their arrival ("healthy immigrant effect"), but their health deteriorates over time spent in Germany. We show that the convergence in health is heterogeneous across immigrants and faster among those working in more physically demanding jobs. Immigrants are significantly more likely to work in strenuous occupations. In light of these facts, we investigate whether changes in the spatial concentration of immigrants affect natives' health. Our results suggest that immigration reduces residents' likelihood to report negative health outcomes by improving their working conditions and reducing the average workload. We show that these effects are concentrated in blue-collar occupations and are larger among low educated natives and previous cohorts of immigrants.