Background: A colostomy is a major surgery, so assessment of self-care practice and self-efficacy among patients with a colostomy is very important and essential to enhance patient's adaptation. Aim: To assess self-care practice and its associated variables among colostomy patients. Research Design: A descriptive design was employed. Subjects: the data were gathered from all adult participants (50 patients) in 9 months. Setting:  study was conducted at the outpatient clinics at AL-Azhar University Hospital in New Damietta City. Tools: Tool I: structured questionnaire to assess the knowledge of patients' self-care practice regarding colostomy care Tool II: Patient's practice observational checklist to assess patients' self-care practice regarding colostomy care Tool III:  colostomy Self-Efficacy Scale to assess coping with difficulties of daily colostomy care. Results: The study revealed that 84%of colostomy patients had inadequate practice, and 0% of patients had self-efficacy regarding colostomy care. Conclusion: The studied patients had lack of self-care practice and self-efficacy regarding colostomy care. Recommendations: Developing and implementing educational programs for patients with colostomy in order to improve their self-care practice and self-efficacy regarding colostomy care.