Background: Colostomy is a surgically created opening in the abdomen in which a piece of the colon is brought outside the abdominal wall to create a stoma through which digested food passes into an external pouching system. Aim of study: Was to evaluate the effect of educational self-care protocol for colostomy patients on peri-stomal skin complications. Research design: Quasi-experimental research design was used to conduct this study. Setting: The study was conducted at General Surgical Department and Out Patients' Clinic at Benha University Hospital. Sample: Purposive sample of 60 adult patients from both gender with age ranging from 20 to 60 years old and have permanent stoma were involved in this study. Tools: Three tools were used in this study. I: A structured interviewing questionnaire. II: Self-care performance checklist and III: The peri-stomal skin DET assessment. Results: Less than half of the studied patients had satisfactory total knowledge regarding colostomy pre self-care protocol implementation which increased to three quarters post self-care protocol implementation, one third of them had satisfactory total self-care practices pre self-care protocol implementation which increased to 86.7% post self-care protocol implementation. Conclusion: The self-care protocol succeeded to improve the studied patients' knowledge and practices regarding colostomy as well as to reduce the severity of the peristomal skin complication. Recommendations: Further study should be carried out on the aspect of improving the colostomy patients' physical and psychological health as well as the patients' quality of life.