Tele-nursing is considered one of the most important technological events of the late (twentieth) century as the gateway to modern nursing care. The aim of tele-nursing is to improve patient safety, quality of care, and is considered a quick access to nursing care by overcoming the geographical barriers. Aim: This study aims to determine the effect of tele-nursing about life style modification on health outcomes of rheumatic heart disease patients during COVID-19 pandemic. Design: A quasi-experimental research design has been utilized in this study (Two groups study and control). Setting: The study was conducted at Sohag University Hospital in Egypt. Subjects: Based on the population, 60 patients were chosen as the sample size was divided in to two groups, control (30 patients) and study (30 patients). Tools:1) A Self-administered Questionnaire (pre/post-tests), (2 Mini Nutritional Assessment short-form (MNA®-SF) (pre/post-test), (3 The Exercise Adherence Rating Scale (EARS) and (4 Deep venous thrombosis risk assessment tool . Results: There were a highly statistically significant differences between both groups regarding knowledge level, proper nutrition, exercise adherence (P≤ 0.001).There was a positive correlation between body mass index and prevention of deep venous thrombosis among study group patients post- implementing of tele-nursing during COVID-19 (r= .580 at P≤ 0.01). Conclusion: it is an effective strategy, telenursing has been proven to give appositive result for improving health outcomes of rheumatic heart disease patients. Recommendations: Replication of the study using large probability sampling. Enhance telenursing use in nursing practice, and apply telenursing via follow up phone services to improve patient’s adherence to a healthy regimen.