Background: Morbidity and mortality from coronavirus are more likely in vulnerable groups, such as cancer patients. Implementing self-care education for prevention in these patients is a priority. This study aimed to investigate the effect of telenursing education on self-care behaviors that prevent COVID-19 in cancer patients.
Methods: This interventional study was conducted at Vasei Sabzevar Hospital on patients with various types of cancer undergoing chemotherapy and radiation therapy in 2020 coinciding with the second peak of COVID-19, for one month (30 minutes daily). Two-stage sampling was conducted in the intervention group (31 participants) and the control group (26 participants). Self-care and patient follow-up training on the prevention of COVID-19 were conducted through WhatsApp. Data were collected using a researcher-made self-care questionnaire, a demographic questionnaire, and a medical information form. 
Results: The mean age of the participants was 58.24±13.27 years, with the majority being female (n=35; 61%). Breast cancer was the most common cancer among the studied subjects (n=24; 42.1%). In the intervention group, the mean score of self-care before the intervention was 21.65±8.72 and after the intervention, it was 36.76±3.14. The results of the independent t-test showed a significant difference between the two groups (P<0.001). Fisher’s exact test did not indicate a significant difference between the two groups in terms of COVID-19 morbidity (P=0.118). 
Conclusion: The results of the present study showed that telenursing education improves self-care behaviors in the prevention of coronavirus in cancer patients.