The United States Department of Agriculture (USDA) initiated the National Animal Health Monitoring System (NAHMS) in 1983 to collect, analyze, and disseminate data on animal health, management, and productivity in U.S. domestic livestock populations. The purpose of this study was to determine the national seroprevalence of Toxoplasma gondii and Trichinella spiralis in grower/finisher pigs using sera collected during the 5th national swine study (NAHMS 2012). Sera was collected during the voluntary survey of 202 grower/finisher swine production sites located in 13 states, accounting for ~90% of U.S. swine production (Iowa, Illinois, Indiana, Kansas, Minnesota, Missouri, Nebraska, North Carolina, Ohio, Oklahoma, Pennsylvania, South Dakota, and Texas). Sera and data on management practices at each surveyed site were collected beginning in July, 2012. Sera were analyzed for antibodies to T. gondii and T. spiralis using 2 commercially available kits. A total of 5,688 sera were tested. Toxoplasma seroprevalence was found to be 3.79%. A single sera was found to be positive for Trichinella; further investigation demonstrated that this sera was collected from a poorly managed farm where pigs were kept outdoors with potential access to wildlife. Previous studies have shown that increased risk of infection with Toxoplasma is associated with the presence of domestic cats, feral cats, and wildlife, swine access to the outdoors, poor practices for disposal of swine carcasses, and the lack of barn-only boots in infected production sites. Increased risk of infection with Trichinella is known to be associated with access to wildlife and poor practices for disposal of swine carcasses. These results suggest that good production practices can be implemented to greatly reduce the risk of exposure to Toxoplasma and Trichinella in confinement-raised pigs, and that pigs with access to the outdoors are at greater risk for acquiring both T. gondii and T. spiralis.