Introduction: Breast cancer is one type of cancer that is the most common cause of death in women, after cervical cancer. The effects of chemotherapy treatment on breast cancer often cause patients to stop treatment. Breast cancer patients must have high self-efficacy in making decisions and taking action on their health. This study aims to determine the self-efficacy of breast cancer patients undergoing chemotherapy.

Methods: This research is a descriptive study conducted at a hospital in the city of Makassar. The number of respondents as many as 46 people who were determined according to the inclusion criteria, data collection used a self-efficacy questionnaire consisting of 5 items and 25 questions.

Results: 60.9% of respondents have high self-efficacy in carrying out activities/activities, 97.8% of respondents have high self-efficacy in obtaining information about the disease/complaints experienced, 100% of respondents have high self-efficacy in receiving assistance from community, family and friends, 97.8% of respondents have high self-efficacy in dealing with diseases and symptoms of breast cancer, and 95.7% of respondents have high self-efficacy in dealing with depression.

Conclusion: In general, respondents have high self-efficacy from 5 items of self-confidence during  chemotherapy.