Abstract: A mold assembly for molding ribbed food patties in a food patty molding machine of the kind having a mold plate, including at least one mold cavity, sliding reciprocally in surface-to-surface engagement between two closure plates, from a fill position to a discharge position and back to the fill position. In the mold assembly, a series of rib-forming channels, each of uniform cross-sectional shape, are formed in the mold plate engaging surface of one closure plate, each channel receiving a close-fitting complementary rib-forming projection on the engaged mold plate surface. The rib-forming channels and projections extend parallel to the path of movement of the mold plate. Supplemental edge rib pockets or projections may be provided in the mold cavity.