Eleutherodactylus cuaquero from the Monteverde Forest Reserve in the Cordillera de Tilaran, Costa Rica, is described as new. The species appears to be closely allied to El. andi of central montane slopes of Costa Rica. Both forms appear to be members of the fitzingeri species group. El. cuaquero is unique in the family Leptodactylidae in the condition of the jaw muscles with three major slips to the depressor and only an externus adductor (formula: DFSQAT + e).