The dyslipidemia of chronic renal failure may worsen after the commencement of continuous ambulatory peritoneal dialysis (CAPD). The purpose of this study was to relate baseline and longitudinal changes in the lipid profile to anthropometrics (weight, mid-arm circumference), aspects of treatment (albumin, total protein losses, peritoneal solute transport [dialysate:plasma ratio of creatinine], dialysate caloric load), total calorie intake (cal/kg), preexisting cardiovascular comorbidity, and survival. Lipid profiles (triglycerides [TG], total cholesterol [TC], and HDL) were measured, along with the above factors, every 6 mo in an unselected prospective cohort of 124 patients who were not treated with lipid-lowering drugs, commencing CAPD between 1990 and 1993, until 1995. On univariate analysis, age, plasma albumin, cardiovascular disease, baseline TG, and TC:HDL ratio predicted survival. Simultaneous multiple Cox regression including all of the significant predictors demonstrated that either high TG or TC: HDL still predicted death, both in patients with and without clinically overt cardiovascular disease. Between 6 and 36 mo of treatment, TC, TG, and TC:HDL were elevated when compared with the baseline, more so in patients with preexisting cardiovascular disease (P < 0.05). Throughout this period, weight and mid-arm circumference correlated positively with TG and negatively with HDL. There were positive correlations between TC and albumin levels for 12 mo after commencement of treatment, but otherwise there were no significant or consistent relationships between lipid profiles and total protein losses, dialysate calorie load, or total cal/kg or solute transport. The worsening dyslipidemia associated with CAPD was not associated with aspects of treatment such as glucose load or protein losses. The strongest predictors of worsening lipid profiles were weight gain and preexisting cardiovascular comorbidity.