A customized unicompartmental tibial cutting guide for orthopedic surgery is provided. The tibial cutting guide includes a first mating surface having a customized patient-specific negative contour to match a corresponding contour of an anterior region of a tibia of a patient and a second mating surface extending transverse to the first mating surface to a midpoint of a tibial plateau of a medial or lateral condyle of the tibia. The second mating surface includes a customized patient-specific negative contour to match a corresponding contour of a mid-region of the tibial plateau of the medial or lateral condyle. The second mating surface is limited to a region between an intercondyloid eminence and a lateral or medial edge of the tibial plateau. The tibial cutting guide also includes a first cutting guide surface and a second cutting guide surface positioned transverse to the first cutting guide surface.
