The authors formally investigated a major international wildlife wholesaler and subsequently confiscated more than 26,400 nonhuman animals of 171 species and types. Approximately 80% of the nonhuman animals were identified as grossly sick, injured, or dead, with the remaining in suspected suboptimal condition. Almost 3,500 deceased or moribund animals (12% of stock), mostly reptiles, were being discarded on a weekly basis. Mortality during the 6-week "stock turnover" period was determined to be 72%. During a 10-day period after confiscation, mortality rates (including euthanasia for humane reasons) for the various taxa were 18% for invertebrates, 44.5% for amphibians, 41.6% for reptiles, and 5.5% for mammals. Causes of morbidity and mortality included cannibalism, crushing, dehydration, emaciation, hypothermic stress, infection, parasite infestation, starvation, overcrowding, stress/injuries, euthanasia on compassionate grounds, and undetermined causes. Contributing factors for disease and injury included poor hygiene; inadequate, unreliable, or inappropriate provision of food, water, heat, and humidity; presumed high levels of stress due to inappropriate housing leading to intraspecific aggression; absent or minimal environmental enrichment; and crowding. Risks for introduction of invasive species through escapes and/or spread of pathogens to naive populations also were identified.