The aim of this study was to quantify the effect of different mortality risk factors in peritoneal dialysis and to establish a prognostic index that could predict mortality risk when patients start dialysis. A prospective study was performed on 103 patients included in our peritoneal dialysis program. The mean follow-up time was 26 +/- 21 months. A multivariate analysis (Cox regression was made to identify different risk factors that could influence patient survival during peritoneal dialysis. Age, gender, parathyroid hormone, albumin, cholesterol, and the presence of diabetes mellitus were evaluated as potential risk factors. Patients were distributed in three groups (high, medium and low risk), according to the risk factors with a significant influence in multivariate analysis, and patient survival was studied depending on the prognostic index using Kaplan-Meier estimator. Overall patient survival was 90% (95%CI: 83 to 96%) after the first year and 40% (95%IC: 32 to 58%) after 5 years of follow-up. The Cox regression analysis identified albumin below 4 g/dL (RR: 2.57; 95% CI: 1.16 to 5.72), age older than 65 years RR: 3.10; 95%IC: 1.20 to 7.98) and diabetes mellitus (relative risk, RR: 4.36; 95%IC: 1.43 to 13.31) as independent risk factors for mortality in patients receiving peritoneal dialysis. Patient survival after two years was 40% (95%IC: 31 to 59%), 73% (95%IC: 60 a 86%) and 100% (p < 0.05), respectively. Malnutrition and related factors in patients receiving peritoneal dialysis are associated with a higher mortality rate.