Background Several factors play a role in the pathogenesis of pruritus in uremic patients. The pathophysiology is complex and many factors have been identified in these patients. The aim of this study was to investigate the presence, severity, and possible causes of pruritus in patients with peritoneal dialysis (PD) . Methods Eighty patients, who received continuous ambulatory peritoneal dialysis (CAPD) treatment, were included in this study. Biochemical measurements, parathormone, C-reactive protein (CRP), and vitamin B12 levels of all the patients were recorded. Furthermore, substance P (SP) levels were measured by ELISA methods. Patients were examined by a dermatologist and pruritus degrees were queried using the visual analog score (VAS) with skin dryness. Results In generalized linear model analysis, total urea clearance and SP independently predicted VAS scores. SP was significantly predictive in ROC analysis in identifying the VAS score in patients with peritoneal dialysis. The sensitivity and specificity of SP were 80% and 67% (cut-off > 364), respectively, with an area under the ROC curve of 0.757 (95% CI 0.650-0.865, p < 0.001). SP also was significantly predictive in ROC analysis in identifying xerosis in PD patients. Conclusion Pruritus was proportional to the amount of substance P and total urea clearance was another reason affecting pruritus in peritoneal dialysis patients.