Objective To investigate the influence of peer education on maintenance knowledge of patients with peripherally inserted central catheter (PICC) outside the hospital.Methods 74 patients with PICC were divided into the intervention group and the control group with 37 patients in each group according to the random digit table,the intervention group received peer education and the conventional health education,while the control group only received routine health education.The maintenance knowledge of PICC was investigated with questionnaires and the results were analyzed.Results xfter intervention,the maintenance knowledge of the intervention group was significantly higher than that of the control group [(36.95±2.84) scores vs.(31.78 ± 4.79) scores,t=5.639,P＜0.05].The incidence rate of complications in the intervention group was lower than that of the control group [21.6％ (8/37) vs.62.2％(23/37),x2=12.491,P＜0.01].Conclusions The peer education can improve patients' maintenance knowledge about PICC and reduce the occurrence rate of the complications of PICC.