To compare the efficacy and safety of straight and J-shaped passive-fixation atrial leads we retrospectively analyzed the results of 100 consecutive implantations of atrial leads at one institution. There were seven cases of upgrades of VVIR to DDDR systems and in one case an active-fixation lead was chosen as a primary approach. These eight patients were excluded from the analysis. The final study group consisted of 92 cases (69 DDDR, 23 AAIR), 69 were J and 23 straight leads. The stimulation threshold, slew rate, impedance, P wave amplitude, and procedural time did not differ significantly between the two types of leads used. During the long-term follow-up of 6-53 months (30 +/- 11.9 months), replacements using active-fixation leads were required in two patients with straight leads and three patients with J leads (P = NS). In addition, one J lead showed signs of damage (impedance > 3,000 Ohm). Long-term follow-up values of the stimulation thresholds and P wave amplitudes did not differ between the groups (P = NS). Transesophageal echocardiography performed in 13 patients revealed a trend toward more distal placement of straight leads within the right atrial appendage. In conclusion, J-shaped leads do not seem to be superior to the straight leads for atrial implantations.