Demagnetizing effects appearing in finite superconductors in the presence of an applied field have important consequences in their magnetic response. In this work we calculate the magnetization and current and field profiles resulting from applying a magnetic field to finite superconducting cylinders in the critical state. By considering different cylinder dimensions, from the infinite cylinder to the thin disk case, we study first how the shape of the magnetization loops gradually change from the known result for infinite samples to a loop having its maximum located at the central position for thin disk. We next describe the important effect that demagnetizing fields have in the relation between the shape of the hysteresis loop and the critical current density of the superconductor. © 2000 Elsevier Science B.V. All rights reserved.