The peritoneal equilibration test (PET) is used as a tool for dialysis prescription. In order to establish which parameters can predict peritoneal transport type, we studied 55 patients on continuous ambulatory peritoneal dialysis (CAPD), who were subjected to a standard PET. Clinical data (sex, age, calculated body surface area [BS], average time on dialysis [TD], and presence of diabetes mellitus), laboratory variables, (serum creatinine [SCr] blood urea nitrogen [BUN], serum albumin [SA], and residual renal function), and adequacy parameters (dialysate creatinine clearance [CrCl], weekly clearance of urea normalized to total body water [KT/V], protein catabolic rate, and dialysis index), were obtained and recorded at the time of the PET. The study group was composed of 29 males and 26 females, mean age of 43.5 +/- 16 years, and average TD of 25.2 +/- 18 months. PET results: 13 patients were low, 16 low average, 19 high average, and 7 high peritoneal transporters. According to the logistic regression analysis, the factors significantly associated with the type of peritoneal transport were: BS, SA, dialysate CrCl, and TD (coefficients 7.2, -1.23, 0.72, and -0.03, respectively). Greater BS and lower SA directly correlate with high peritoneal transport, and are the strongest predictors for the model.