Background A colostomy is a surgery that makes a temporary or permanent opening called a stoma. A stoma is a path that goes from the large intestine to the outside of your abdomen. Aim of study: the study aimed to assess knowledge and performance of nurses about colostomy care among old age in Beni-Suef. Subjects and methods: A descriptive design was used to achieve the aim of the current study. The study was conducted in surgical departments male and female at Beni-Suef university hospital, Beni-Suef specialized hospital, and health insurance hospital. Convenient sample was used for this study; include all nurses (78 nurses) working in surgical departments at Beni-Suef university hospital (44 nurses), Beni-Suef specialized hospital (13 nurses), and health insurance hospital (21 nurses). Three tools for data collection were used to carry out the current study namely; socio-demographic questionnaire sheet, questionnaire sheet for nurses' knowledge regarding colostomy care, and ostomy care observation checklist. Results: More than half (57.7%) of studied nurses their ages were less than 30 years. More than two thirds (67.9%) of studied nurses are females. More than half (60.3%) of them had nursing health institute. Conclusion and recommendations: Nearly half of nurses had satisfactory level of total knowledge about colostomy care., more than one third of nurses had satisfactory level of total performance about colostomy care. Periodic assessment for knowledge of nurses about colostomy care among old age in Beni-Suef. Periodic assessment for performance of nurses about colostomy care among old age in Beni-Suef