Background: Mindfulness based intervention program offers an effective way of reducing stress among elderly with colorectal cancer. Aim: This study aimed to evaluate the effect of mindfulness based intervention program on stress reduction among elderly with colorectal cancer. Design: Quasi experimental design was utilized in this study. Setting: This study was conducted on oncology institution and outpatient clinic of Sohag University Hospitals. Sample: Purposive sample was used in this study included 327 elderly. Tools: Two tools were utilized to collect data. Tool I: A structured interview questionnaire. It was consisting of three parts: demographic characteristics of the elderly, medical history and knowledge. Tool II: Part I: Mindful attention awareness scale. Part П: Perceived stress scale. Result: 10% of elderly had good total knowledge pre intervention program, improved to 90% post implementation of intervention program, 50% of elderly had high stress in the last month pre intervention program improved to 70% of elderly had low stress in the last month post intervention program, 30% of elderly had high mindful attention awareness pre intervention program improved to70% of elderly had high Mindful Attention Awareness post intervention program. Conclusion: The results of the present study suggest the effectiveness of mindfulness based intervention program on reduction of stress level in colorectal cancer elderly. Recommendation: Continuous education program for all elderly about effect of mindfulness based intervention program on stress reduction for elderly with colorectal cancer.