Mycoplasmas isolated from the throats of a rhesus monkey and a baboon within 3 days of their arrival from India were shown to be serologically distinct from 104 previously recognized Mycoplasma and Acholeplasma spp. Two mycoplasma colonies were cloned and examined in detail for morphology, growth, and biochemical characteristics. The two strains were closely related and had the following properties: guanine-plus-cytosine content of 32 mol%, requirement for sterol, arginine hydrolysis, and anaerobic growth. Glucose was not metabolized, and urea was not hydrolyzed. Strain 3T (= NCTC 11728) is the type strain of a new species, Mycoplasma indiense.