Purpose: This study was designed to fine out the relationships among body image, self-esteem and health promotion behavior in mastectomy patients. Method: Data were obtained by self -reported questionnaires from 218 patients undergone mastectomy from September 1 to October 15, 2005. And data were analyzed using SPSS/PC WIN 12.0 program. For the statistical analysis of the date, frequency and percentage, mean and standard deviation, t-test, ANOVA and Scheffe test and Pearson's correlation coefficients were used. Result: The mean scores of the body image, self-esteem, and health promotion of the subjects were $41{\pm}7.40$ (range of scale : 17 to 68), $22.22{\pm}4.95$ range of scale : 10 to 40), and $130.45{\pm}23.99$ range of scale : 50 to 200), respectively. There were significant differences with the score of body image by the work type (F=4.018, p= .008), a number of child (F=3.069, p= .029), and participation with self help group program (t=68.177, p= .001). There were significant differences with the score of self-esteem by the type of religion (F=4.546, p= .002), work type (F=4.488, p= .004), post operation period (F=2.814, p= .026), and participation with self help group program (t=12.901, p= .001). There were significant differences with the score of the health promotion behavior by the type of religion (F=3.066, p= .018), economic state (F=11.765, p= .001), level of education (F=6.285, p= .001), operation site (F=.368, p=.027), family history (t=6.557, p= .011), and hope of breast reconstruction (t=7.025, p=.009). Relationship between body image and self-esteem showed moderate positive correlation (r=0.631, p= .001). The relationship between body image and health promotion behavior showed slightly positive correlation (r=0.257, p= .001). The relationship between self-esteem and health promotion behavior showed moderate positive correlation (r=0.431, p=.001). Conclusion: For the increasement of the health promotion behavior, it is needed to improve body image and self-esteem in mastectomy patients. And, It is needed to encourage to participate with self help group program in mastectomy patients.