Objective To describe self-concealment in rectal cancer patients with ostomy and to evaluate the influencing factors. Me-thods Data collection occurred at four hospitals′ wards and clinics. A convenience sample of 220 rectal cancer patients living with ostomy participated in the study. The General information questionnaire, Self-Concealment Scale（SCS）, Social Impact Scale（SIS）、and Medical Coping Modes Questionnaire（MCMQ） were completed by them. Results The rectal cancer patients living with ostomy scored (30.44±10.58) points in SCS, with 72（32.7%） cases at high level of concealment. Univariate analysis showed that family locations, marital status, occupation status and personal monthly income had a significant impact on patients′ self-concealment （P＜0.01 for all）. Multiple linear regression analysis showed that stigma and acceptance-resignation coping strategy accounted for 66.80% of the total variance for self-concealment （P＜0.01）. Conclusion Rectal cancer patients with colostomy demonstrated a moderate level of self-concealment, with 32.7% at high level of soncealment. Stigma and coping style were its predicting factors. Medical staff can provide a platform to facilitate doctor-nurse-patient communication, give guidance and encouragement to the patients, help them face facts, so as to mitigate the level of stigma.