We have imaged vortices in superconducting thin films with a low-temperature magnetic force microscope that utilizes microfabricated piezoresistive cantilevers with built-in tips. The films of YBa2Cu3O7-delta and Bi2Sr2Ca1Cu2O8+x, are made by laser ablation and molecular beam epitaxy, respectively, The vortices usually appear as round features in the noncontact image with a diameter of about 1 mu m or slightly less. In some cases the position of the vortices is correlated to defects observed in the topographic image of the same area. The vortices move sometimes, especially after taking a topographic (contact mode) scan.