Anew species of Paratelmatobius is described from Parque das Neblinas at Serra do Mar in Bertioga Municipality, State of São Paulo, Brazil. The new species, included in the P. cardosoi species group, is diagnosed by its larger size among the species of the group; tympanum visible externally; vocal slits present in males; presence of tubercles on the upper eyelid; well developed tubercle at base of mandible; dorsolateral fold developed; large black spinous nuptial pad on thumb in males; first finger longer than second; belly, ventral surface of arm and forearm, and external margin of throat blotched with orange-reddish spots.