To study the prevalence and pathogenesis of uremic pruritus, CAPD and HD patients were asked to complete a questionnaire. The replies were quantitated based on numerical scales, and the results were compared with various hematological and biochemical parameters, underlying disease, and duration of dialysis. There were 113 CAPD patients (63 males and 50 females), mean age 60 (range 20-84) years, average time on CAPD 20 (range 1-163) months and 76 HD patients (44 males and 32 females) mean age 57 (range 23-81) years, mean time on HD 44 (range 2-242) months. Replies to questions were evaluated and graded by the same investigator who did not know the patients. Pruritus was present in 70 (62%) CAPD patients (64% in females and 60% in males p = NS) and in 41 (54%) HD patients (69% in females and 43% in males, p = 0.025). Before starting dialysis pruritus was present in 30% CAPD patients and 28% HD patients. Pruritus was graded as mild, moderate and severe; the distribution was 58.6%, 34.3%, and 7.1% (CAPD) and 43.9%, 41.5%, and 14.6% (HD), respectively. Dry skin was reported by 73% CAPD patients and 72% HD patients. This xeroderma was correlated with the severity of pruritus and was also present in 65% CAPD and 48.5% HD patients without pruritus. Patients with pruritus were older than those without pruritus both for CAPD (63 vs 54 years, p = 0.004) and HD (61 vs 51 years, p = 0.003). A significant correlation was observed only between pruritus score and age for CAPD patients.(ABSTRACT TRUNCATED AT 250 WORDS)