Purpose: This study was conducted to identify the impact of fatigue, pain, anxiety and depression on the quality of life (QOL) among breast cancer patients. Methods: This study was conducted from July 12th to July 20th, 2010. One hundred and fifty breast cancer patients were recruited from D city in Korea. The instruments used in this study were the fatigue, pain, anxiety, depression and the quality of life scales for patients with breast cancer. Data were analyzed using descriptive statistics, t-test, ANOVA, Pearson correlation coefficients and multiple regression with the SPSS/WIN 12.0 program. Results: The quality of life for cancer patients showed a significant relationship with fatigue, pain, anxiety and depression. The significant factors influencing quality of life were fatigue, pain, anxiety and depression that explained 65.6% of the variance. Conclusion: Patients with breast cancer experienced fatigue, pain, anxiety and depression which led to a negative effect on quality of life. The results suggest that intervention programs to reduce fatigue, pain, anxiety and depression could improve the quality of life for breast cancer patients.