■ Objective: To determine if intradialytic parenteral nutrition (IDPN) therapy of malnourished hemodialysis patients results in a decrease in hospitalization rate and mortality. ■ Data sources: Outpatient hemodialysis records, patient interviews, registered dietitian evaluations, and hospitalization discharge summaries. ■ Study selection: All hemodialysis patients treated with IDPN from July 1, 1989, until March 15, 1991, death, or cessation of IDPN. All patients had to meet criteria defining malnutrition and to have failed 2 weeks of intensive dietary counseling with (64%) or without (36%) dietary supplements. ■ Data extraction: Data base abstracted by two registered nurses skilled in data collection and familiar with hemodialysis. Data were collected, and patients were evaluated on a monthly basis. ■ Data synthesis: Responders (Rs) were those with a greater than 5-g/L (0.5-g/dL) increase in albumin or total protein or a greater than 10% nonfluid weight gain. Rs differed from nonresponders (NRs) in baseline values for albumin (22 ± 7 g/L [2.2 ± 0.7 g/dL]; 30 ± 9 g/L [3.0 ± 0.9 g/dL]; P < .0001) and total protein (53 ± 10 g/L [5.3 ± 1.0 g/dL]; 62 ± 13 g/L [6.2 ± 1.3 g/dL]; P < .01). There was a significant increase in body weight in Rs versus NRs (3.5 ± 5.4 kg, -0.5 ± 0.3 kg; P < .0001). There was no difference in International Classification of Diseases-9-CM (ninth revision, Clinical Modification) diagnoses or demographics. Mortality was different for Rs versus NRs (9/52 v 11 /20; P = .0001) as was the hospitalization rate before (0.36 ± 0.23 v 0.25 ± 0.20 episodes/patient month; P < .0001) and during (0.12 ± 0.20 v 0.25 ± 0.26 episodes/patient month; P < .0001) IDPN treatment. Of the living Rs, 26 (50%) were able to discontinue IDPN by increasing oral intake to more than 90% of the prescribed diet. ■ Conclusion: IDPN may be related to increased serum albumin and total protein concentrations in subsets of malnourished hemodialysis patients. There may also be a link between decreased hospitalizations and mortality in patients who respond to IDPN. Differences in Rs and NRs could not be found to explain these findings. ■ Objective: To determine if intradialytic parenteral nutrition (IDPN) therapy of malnourished hemodialysis patients results in a decrease in hospitalization rate and mortality. ■ Data sources: Outpatient hemodialysis records, patient interviews, registered dietitian evaluations, and hospitalization discharge summaries. ■ Study selection: All hemodialysis patients treated with IDPN from July 1, 1989, until March 15, 1991, death, or cessation of IDPN. All patients had to meet criteria defining malnutrition and to have failed 2 weeks of intensive dietary counseling with (64%) or without (36%) dietary supplements. ■ Data extraction: Data base abstracted by two registered nurses skilled in data collection and familiar with hemodialysis. Data were collected, and patients were evaluated on a monthly basis. ■ Data synthesis: Responders (Rs) were those with a greater than 5-g/L (0.5-g/dL) increase in albumin or total protein or a greater than 10% nonfluid weight gain. Rs differed from nonresponders (NRs) in baseline values for albumin (22 ± 7 g/L [2.2 ± 0.7 g/dL]; 30 ± 9 g/L [3.0 ± 0.9 g/dL]; P < .0001) and total protein (53 ± 10 g/L [5.3 ± 1.0 g/dL]; 62 ± 13 g/L [6.2 ± 1.3 g/dL]; P < .01). There was a significant increase in body weight in Rs versus NRs (3.5 ± 5.4 kg, -0.5 ± 0.3 kg; P < .0001). There was no difference in International Classification of Diseases-9-CM (ninth revision, Clinical Modification) diagnoses or demographics. Mortality was different for Rs versus NRs (9/52 v 11 /20; P = .0001) as was the hospitalization rate before (0.36 ± 0.23 v 0.25 ± 0.20 episodes/patient month; P < .0001) and during (0.12 ± 0.20 v 0.25 ± 0.26 episodes/patient month; P < .0001) IDPN treatment. Of the living Rs, 26 (50%) were able to discontinue IDPN by increasing oral intake to more than 90% of the prescribed diet. ■ Conclusion: IDPN may be related to increased serum albumin and total protein concentrations in subsets of malnourished hemodialysis patients. There may also be a link between decreased hospitalizations and mortality in patients who respond to IDPN. Differences in Rs and NRs could not be found to explain these findings.