Background/Aims: Studies on the risk factors and outcomes of peritonitis within the first 6 months in peritoneal dialysis patients are sparse. This study aims to investigate the risk factors associated with early-onset peritonitis (EOP) and its influence on patients’ technique survival and mortality. Methods: This is a retrospective observational cohort study. A total of 483 patients who had at least one episode of peritonitis were enrolled and followed from March 1, 2002, to August 31, 2016, at our center. According to the time to first peritonitis, we divided patients into two groups: EOP (≤ 6 months, n=167) and late-onset peritonitis (LOP, >6 months, n=316). Logistic regression was used to analyze the factors associated with EOP. A Cox proportional hazards model was constructed to examine the influence of EOP on clinical outcomes. Results: Of the 483 patients, 167 (34.6%) patients developed their first episode of peritonitis within the first 6 months. The EOP patient group had more male patients, a shorter time on peritoneal dialysis (PD), lower serum albumin levels at the time of PD initiation and a higher peritonitis rate (P