A retrospective study on the results of 116 permanent ventricular pacemaker implantations performed in the Service of Cardiology of the Hospital Clinico Universitario in Salamanca is reported. In the majority of cases the indication for a pacemaker was a complete atrioventricular block (53 cases). Sixteen cases had a "sick-sinus syndrome". An apparent cardiopathy was not found in 84 percent of the cases. In the group of patients with cardiopathy that of ischemic type was the most common. The technique of endocardiac catheter pacing was employed in all cases. An 18 percent of global complications occurred, but in no case an early electrode displacement was registered. Complications appeared at a later time included erosion of the pacemaker in ten cases, and displacement and/or deinsertion in seven. The mean life for 18 displaced generators was 41.3 months. A sudden equipment malfunction occurred in two cases, and an inhibition by potentials of the pectoralis major muscle in another. Morbidity rate was lower to that of other published series, may be due to the use of modern generators with a progressive reduction of its diameter and weight and more flexible electrodes which allow a better implantation. The mortality rate was zero.