Abstract: Background: Stress produces several physical and mental symptoms, and the effects of stress differ depending on each individual's situational factors. Purpose: of this study was to examine the effect of stress self-management intervention on enhancing stress levels, self-efficacy, and outcomes of older adults with varying chronic diseases (diabetes and hypertension). Design: A quasi-experimental (study and control design) was utilized. Settings: - This study was conducted at a family health unit in Sahel El-Gawaber village, Menoufia Governorate, Egypt. Sample: This study included a purposive sample of 140 older adults in the above setting, Egypt.  Instruments: three instruments were utilized as follow: instrument I: Interviewing questionnaire that included; the socio-demographic data of older adults, medical history, and bio-physiological measurement instrument which included random blood sugar and measurement of blood pressure. Instrument II: The Perceived Stress Scale was used to assess perceived stress in older adults. Instrument III:  Self-Efficacy for Managing Chronic Disease Scale.  Results: After the intervention, there was a significant decrease in stress among the study group than the control group. Also, the blood glucose level and blood pressure were controlled in the study group than control group. Conclusions: stress self-management intervention was effective in stress control among older adults in the study group compared to the control group. Also, it was successful in controlling blood glucose and blood pressure in the study group than control group. Recommendations: Enhance awareness of the community regarding stress management. The nurse should take a more active role in providing educational programs about stress management.