In 1973 the Convention in International Trade in Endangered Species of Wild Fauna and Flora (CITES) was called to life as to regulate the international wildlife trade, and to prevent species becoming (economically and biologically) extinct. The trade in freshwater turtles and tortoises in Asia is so huge that it threatens the survival of many species. In 2006 and 2007, during three surveys at Chatuchak market in Bangkok, Thailand, we recorded a significant trade in non-native CITES-listed freshwater turtles and tortoises to be used as pets. We documented a total of 688 individuals of 19 species from different regions of the world, many of which are globally threatened with extinction. Most commonly recorded were three species of tortoise from Madagascar and Africa, i.e. Radiated Tortoise Geochelone radiata, Spurred Tortoise G. sulcata and Leopard Tortoise G. pardalis. Five species were listed on CITES Appendix I, precluding all international trade, and an additional six Appendix II or III-listed species that can be traded albeit regulated, were not registered as being imported into Thailand in the last six year. CITES I-listed species were not more expensive than CITES II or III listed species, nor was there a relationship between retail price and numbers of turtles observed. The large number and availability of illegally sourced animals indicates a blatant disregard for law and authority by traders both from Thailand and from exporting countries. We conclude that the trade in these species, in such significant volumes, is of serious conservation concern, and in order for CITES to be more effective it is imperative that Parties recognize the scale of the international trade in freshwater turtles and tortoises and respond accordingly.