A new species of the genus Pseudocalotes (P. khaonanensis n. sp.) from a cloud forest in peninsular Thailand is described. The holotype and paratype of the new species was discovered in San Yen, Khao Nan National Park, Nakhon Si Thammarat. This is the first time that a species of the genus Pseudocalotes has been recorded in peninsular Thailand. Morphological evidence is given which differentiates this species from others in the genus