BackgroundBreast cancer is considered as a major health problem for women, and the prevalence is increasing over the world. Research to improve their quality of life is necessary.PurposeThis study was to examine the body image and self‐esteem of breast cancer patients who underwent breast reconstruction in order to determine whether these affect their quality of life.MethodsA cross‐sectional descriptive design was employed. This study was conducted on 140 patients who underwent breast reconstruction following breast cancer surgery at S University Hospital in Gyeonggi‐do, South Korea. Measures were the general characteristics list, body image scale, self‐esteem scale, and the Korean version of the Functional Assessment of Cancer Therapy‐Breast Cancer Version 4 for quality of life. Data were analysed using descriptive statistics, Pearson correlation coefficient, linear regression, and process macro bootstrapping for mediation effect. Data were collected from October 2020 to March 2021.ResultsThe path regression coefficient was 1.59 (p < .001), and the direct effect of body image on the quality of life was 1.34 (p < .001) considering the effect of self‐esteem, which is a parameter. This confirmed that self‐esteem mediates body image and quality of life. The explanatory power of self‐esteem for quality of life was 54%.ConclusionThis study suggests that body image and self‐esteem are important factors in the quality of life of breast cancer patients who underwent breast reconstruction. Also, the self‐esteem has a mediating effect in the relationship between body image and quality of life.Relevance to clinical practiceIn clinical practice, nurses should focus on the body image and self‐esteem of breast cancer patients who have undergone breast reconstruction in order to improve their quality of life.Patient or public contributionThis cross‐sectional descriptive design study was conducted on patients who underwent breast reconstruction following breast cancer surgery at hospital in South Korea.