According to conventional wisdom, rapidly growing stocks of scrap tires on the U.S.–Mexico border pose a variety of health and environmental risks. This article assesses these risks in Paso del Norte, the border’s second-largest metropolis comprised principally of Ciudad Juárez, Chihuahua, and El Paso, Texas. We find that air pollution from tire pile fires poses the greatest threat. Scrap tires in Paso del Norte do not contribute significantly to the propagation of mosquito-borne diseases or to shortages of space in solid waste disposal sites. The burning of scrap tires at industrial facilities is minimal and might not have significant adverse environmental impacts even if it were more common.