Objective: To compare the improvement in quality of life (QoL) after implantation of leadless pacemakers (L-PM) with that of conventional pacemakers (C-PM) in patients with slow-onset arrhythmias. Methods: A total of 112 patients who received pacemaker implantation for the first time at Beijing Anzhen Hospital from January 2020 to July 2021 were selected, including 50 leadless pacemakers (L-PM) and 62 conventional pacemakers (C-PM). Clinical baseline data were collected, pacemaker-related complications and SF-36 scores were recorded and followed up at 1, 3, and 12 months post-operatively; SF-36 questionnaires and additional questionnaires were completed to compare the quality of life of the 2 groups; and factors associated with the change in QoL from baseline to 1, 3 and 12 months post-operatively were analyzed using multiple linear regression models. Results: The age of the 112 patients was (70.3±10.5) years, and 69 patients (61.6%) were male. The age of patients with L-PM and C-PM was (75.8±8.5) years and (67.5±10.4) years, respectively (P=0.004). In the L-PM group, 50 patients completed 1-, 3-, and 12-month follow-up. In the C-PM group, 62 patients completed the 1-month and 3-month follow-up, and 60 completed the 12-month follow-up. The C-PM group had a higher incidence of discomfort in the surgical area, impact of daily activities for the discomfort in the surgical area, and concern about heart or overall condition than the L-PM group on the additional questionnaire (all P values<0.05). After adjusting for age and SF-36 scores at baseline, at 12th month of follow-up, patients implanted with C-PM had lower values for quality of life PF, RP, SF, RE, and MH scores compared to patients implanted with L-PM, with beta values (95%CI) of -24.500 (-30.010--18.981), -27.118 (-32.997--21.239), -8.085 (-12.536--3.633), -4.839 (-9.437--0.241), -12.430 (-18.558--6.301), respectively (all P values<0.05). Conclusions: L-PM is associated with better QoL in slow arrhythmias patients, and patients who received L-PM reported less activity limitations due to surgical discomfort and less emotional distress.