Contemporary comparisons of mortality in matched hemodialysis and peritoneal dialysis patients are lacking. We aimed to compare survival of incident hemodialysis and peritoneal dialysis patients by intention-to-treat analysis in a matched-pair cohort and in subsets defined by age, cardiovascular disease, and diabetes. We matched 6337 patient pairs from a retrospective cohort of 98,875 adults who initiated dialysis in 2003 in the United States. In the primary intention-to-treat analysis of survival from day 0, cumulative survival was higher for peritoneal dialysis patients than for hemodialysis patients (hazard ratio 0.92; 95% CI 0.86 to 1.00, P = 0.04). Cumulative survival probabilities for peritoneal dialysis versus hemodialysis were 85.8% versus 80.7% (P < 0.01), 71.1% versus 68.0% (P < 0.01), 58.1% versus 56.7% (P = 0.25), and 48.4% versus 47.3% (P = 0.50) at 12, 24, 36, and 48 months, respectively. Peritoneal dialysis was associated with improved survival compared with hemodialysis among subgroups with age <65 years, no cardiovascular disease, and no diabetes. In a sensitivity analysis of survival from 90 days after initiation, we did not detect a difference in survival between modalities overall (hazard ratio 1.05; 95% CI 0.96 to 1.16), but hemodialysis was associated with improved survival among subgroups with cardiovascular disease and diabetes. In conclusion, despite hazard ratio heterogeneity across patient subgroups and nonconstant hazard ratios during the follow-up period, the overall intention-to-treat mortality risk after dialysis initiation was 8% lower for peritoneal dialysis than for matched hemodialysis patients. These data suggest that increased use of peritoneal dialysis may benefit incident ESRD patients.