The Attwater's prairie-chicken (ATPC) Tympanuchus cupido attwateri is facing rapid extinction. Given their long-standing protected status, little information pertaining to the parasites and diseases of this species is available. In an effort to aid in management strategies, we conducted a helminth survey on ATPC that had been released from captivity between 1999 and 2010 in the Texas City Prairie Preserve, Galveston County, Texas. Birds examined were in various stages of decomposition, ranging from little signs of decomposition to advanced stages. Two hundred fifty nematodes representing three species were identified from 16 ATPC. Dispharynx nasuta was the most prevalent helminth species and occurred in 38% of hosts examined. Heterakis gallinarum occurred in 19% of hosts examined and Capillaria contorta infected 31% of hosts examined. Juvenile ATPC are typically treated with anthelmintics (Ivermectin and Panacur) before release in the wild. Although they spent variable (but limited) time in the environment postrelease, nematode prevalence was high.