Illegal wildlife trade is one of the greatest threats to biodiversity. Understanding its economic value is a first step to establishing the magnitude of the problem. We develop a dataset of illegal wildlife trade prices and combine it with seizure data to estimate the economic value of illegal wildlife trade entering the USA. Using 2013 as a reference year, the results reveal that the economic value of illegal wildlife trade entering the USA was, using a conservative scenario where potential outliers were excluded, US$3.2 billion/year (uncertainty range (UR) 5th and 95th percentile of US$0.6–8.2 billion/year) and, without excluding potential outliers, US$4.3 billion/year (UR of US$1.3–9.6 billion/year). Our results for the USA alone are of a comparable magnitude to the lower bound of commonly used global estimates of the economic value of IWT of uncertain origin, suggesting that the global economic value of IWT is currently underestimated and requires an urgent revision.