The results of an experimental investigation of the punching shesr strength of reinforced concrete slabs with varying span-depth ratios are summarized. Ten axisymmetric slabs were tested. The slab thickness was kept constant while the support diameter was varied to produce different span-depth ratios. The punching shear strength was found to significantly increase as the span-depth ratios decreased below 6. Maximum test strengths were nearly 5 times greater than the 1983 ACI Building Code predicted strengths. The higher strengths were a result of smaller span-depth ratios, in-plane compressive forces caused by restraining action at the supports, and excellent anchorage provided for the shear reinforcement.