Objective To investigate pathogens, antibiotics sensitivity and prognosis of dialysis-associated polymicrobial peritonitis, so as to provide evidence for prevention and treatment of polymicrobial peritonitis. Methods A total of 151 peritoneal peritonitis episodes in 81 patients, who received dialysis in our department between January 2008 and September 2010, were analyzed in the present study. The causative pathogens, antibiotics sensitivity and prognosis of polymicrobial peritonitis were retrospectively reviewed in these patients. Results Pathogenic culture of effluent peritoneal dialysate was positive in 98(64.9%) of the 151 peritoneal peritonitis episodes, and 20(13.2%) epidoses were polymicrobial peritonitis. The organisms isolated from the effluent peritoneal dialysate included mixed Gram-positive and Gram-negative organisms (30%), mixed Gram-positive and fungi (30%), mixed Gram-negative and fungi (15%), pure Gram-positive organisms (15%), pure Gram-negative organisms infection (5%), and pure fungi (5%). The sensitive rates of Gram-positive organisms in the polymicrobial peritonitis were 100% to vancomycin, 61% to cefazolin sodium, and 52% to levofloxacin; and those of Gram-negative organisms were 100% to meropenem, 100% to cefoperazone-sulbactam, 70% to gentamycin, and 60% to ceftazidime. Fifteen (75%) of the 20 polymicrobial peritonitis episodes were cured and continuously received peritoneal dialysis. One (5%) patient died and 4 (20%) were converted to permanent hemodialysis. ConclusionPolymicrobial peritonitis in our group has been mainly caused by mixed infection of Gram-positive and Gram-negative organisms, mixed infection of Gram-positive organisms and fungi. The Gram-positive organisms are sensitive to vancomycin, and Gram-negative organisms are sensitive to meropenem and cefoperazone-sulbactam. Earlier catheter removal is necessary for fungal peritonitis or refractory peritonitis.