Mycoplasma species are important pathogens of captive and free-ranging chelonians. Bourret's box turtle (Cuora bourreti) is a critically endangered species of Indochinese box turtle in the family Geoemydidae. Four privately owned wild-caught Bourret's box turtles were presented for clinical evaluation for anorexia and lethargy following shipment from a reptile wholesaler 3 wk prior. Choanal-cloacal swabs of two of the turtles were positive for Mycoplasma sp. by polymerase chain reaction. Sequencing of the 16S rRNA gene and 16S-23S rRNA intergenic spacer was 99% homologous to an unclassified Mycoplasma sp. previously documented in free-ranging and captive North American species of the family Emydidae. The potential of Mycoplasma sp. to induce disease in Bourret's box turtles is unknown. Global trade in live reptiles is believed to have facilitated this potential expansion of host range.