Antibiotics have been used by pig producers for several decades, and are now used routinely. This study documents the current productivity and economic impacts of the use of antibiotics for growth promotion (AGP) by pig grower/finishers at the farm level. We evaluate the impacts of an AGP ban, and use of AGP by all pig grower/finishers for 61S90 days (a more production-efficient level), using data from the National Animal Health Monitoring System Swine 2000 Survey. Findings indicate that pig productivity improves with AGP. Relative to current use, an AGP ban would decrease producer profits by $1,400 per 1,020-head barn, and profits would increase by $1,992 for each grower/finisher barn when AGP is fed for 61 to 90 days. There is increasing concern about the use of antibiotics in animal production, partly because of the selection for antibiotic resistance. Thus, a careful examination of the value of AGP in pork production is warranted.