The U.S. Environmental Protection Agency initiated the National Dioxin Air Monitoring Network (NDAMN) in 1998. NDAMN has three primary purposes: 1. To provide measurements of background atmospheric levels of dioxin-like compounds in different geographic regions of the United States; 2. To determine the the atmospheric levels of dixoin-like compounds in agricultural areas where livestock, poultry, and animal feed crops are grown; and 3. To provide data to evaluate results from long-range transport and deposition air models. At the end of 2001, 32 NDAMN sites were operational. This paper focuses on procedures implemented in NDAMN to assure quality and the results associated with such procedures.