Objective To investigate the Knowledge-Attitude-Practice(KAP)of cancer patients with peripherally inserted central catheter (PICC) and its associated factors. Methods A cross-sectional study was undertaken in 650 cancer patients with PICC in the West China Hospital, Sichuan University, from April 2014 to March 2015. Data were collected through a self-designed questionnaire in relation to KAP and its associated factors. Results A total of 619 valid questionnaires were returned. The participants had an average score of 9.28 ± 2.04 in knowledge, 27.95±4.17 in attitude, and 25.67±4.00 in practice. Occupation was associated with catheter-related knowledge. Comorbidity (with diabetes, hypertension and coronary heart disease) was associated with catheter-related attitudes ( P=0.040).Gender ( P=0.015) and catheter insertion site ( P=0.023) were associated with PICC practice. The multivariable linear regression model showed that female patients (standardized partial regression coefficient =-0.097, P=0.024) and those with a higher level of education (standardized partial regression coefficient=0.125, P= 0.017) had a higher score in PICC practice. Conclusion Overall, a high level of KAP was found in cancer patients with PICC.Clinical nursesshould provide personalized catheter-related education for patients according to their gender and level of education. Special attention should be paid to those with comorbidities such as diabetes mellitus, hypertension, coronary heart disease and other chronic diseases.