Laboratory tests have been carried out in order to study the effect produced by the type and the amount of shear reinforcement on the ultimate loads and the deformations at failure by punching of concrete slabs carried on columns. The results of these tests served as a guide in evolving a theory which affords a basis for design of these slabs. This theory takes into account the strength of materials, the types and the amounts of flexural and shear reinforcement, an well as other dimensional characteristics of the slabs.