This study uses satellite data to detect agricultural straw burnings and estimates its impact on air pollution and health in China. We find that straw burning increases particulate matter pollution and causes people to die from cardio-respiratory diseases. Middle-aged and old people in rural areas are particularly sensitive to straw burning pollution. We estimate that a 10µg/m3 increase in PM2.5 will increase mortality by 3.25%. Subsidizing the recycling of straw brings significant health benefits and is estimated to avert 21,400 pre-mature deaths annually.