Proliferative lymphocytic tracheitis and pneumonia were observed histologically in the respiratory tract of a captive Burmese python (Python molurus bivittatus). A mycoplasma species was isolated from the respiratory tissue. Polymerase chain reaction analysis of the 16S rRNA gene sequence of the isolate showed 0.90 similarity to Mycoplasma agassizii, an organism previously shown to cause respiratory disease in reptiles. Based on these findings, a novel Mycoplasma species was suspected to be the causative agent of respiratory disease in this snake.