The clinical epidemiology of pneumonia in hemodialysis patients has received little attention. We linked the retrospective Waves 1, 3, and 4 Dialysis Morbidity and Mortality Study data sets (n=10 635) to Medicare claims to identify hospitalizations with pneumonia. Mean patient age was 60.3 years and duration of end-stage renal disease (ESRD) 3.8 years; 41.1% of patients had diabetes mellitus. Only 31.6% had received influenza vaccination in the 4 months preceding the study start date (January 1, 1994). The cumulative probability of pneumonia hospitalization was 0.09 at 1 year and 0.36 at 5 years. The main associations of hospitalization with pneumonia were age 45-64 years and >/=65 years (adjusted hazards ratio (AHR) 1.26 and 1.48 vs <45 years), chronic lung disease (AHR 1.62), ESRD duration >/=10 years (AHR 0.75 vs <5 years), body mass index (AHR 0.66 for 25.0-29.9, 0.58 for >/=30 vs <18.5 kg/m(2)), serum albumin (AHR 0.74 for >/=4.06 vs </=3.42), and transplantation as a time-dependent covariate (AHR 0.68). One- and 5-year post-pneumonia survival probabilities were 0.55 and 0.17 (vs 0.76 and 0.29 in the overall study population). Adjusted mortality hazards ratios were 4.08 (95% confidence interval (CI) 3.41-4.89) for the 0- to 6-month interval after pneumonia, 3.04 (95% CI 2.58-3.66) for 6- to 12-months, and 2.31 (95% CI 1.97-2.71) for 12-18 months, and remained approximately twofold thereafter. Hospitalization with pneumonia is common in hemodialysis patients and carries a poor prognosis.