A patient-specific acetabular guide comprises a cup body, a plurality of alignment arms extending from the cup body and engaging periacetabular areas of a pelvis, and a supporting leg protruding from the cup body and abutting against a portion of an acetabular fossa. Each alignment arm has a fixing hole extending inclinedly therethrough to allow a Kirschner pin to pass through and enter the periacetabluar area of the pelvis for positing and orienting the acetabular guide on a predetermined location of an acetabulum.
