To compare the complication rate in patients having a dual chamber versus a single chamber pacing system, 337 consecutive procedures performed during a 3-year period were analyzed prospectively. Two hundred fifty-eight patients (77%) received a VVI pacemaker and 75 (23%) a DDD unit. Thirteen VVI (5%) and 4 DDD (5.3%) needed reintervention. Lead displacement with reoperation was required for three ventricular leads (1%) and one atrial lead (1.3%). Infection occurred in two VVI units (0.77%) and one DDD (1.33%) unit. Muscular stimulation was noticed among three DDD (4%) and nine VVI systems (3.5%). Urgent reprogramming was needed for 23 VVI (9%) and six DDD units (8%). There was no increase in complications with dual chamber pacing compared to single chamber systems.