Purpose: The purpose of this study was to explore the relationship of uncertainty, hope and quality of life in patients with breast cancer. Method: The subjects of the study were 113 breast cancer patients treated at 3 university hospitals in Daegu and Busan from June 1 to September 30, 2003. Uncertainty was measured by the Mishel Uncertainty in Il1ness Scale (MUIS), Hope was measured by Nowotny's Hope Scale, and quality of life by Ro's Korean Quality of Life(QOL). Data was analyzed with the SPSS program by t-test, ANOVA, Spearman's rank correlation and Multiple Regression Analysis. Result: The scores of uncertainty were negatively correlated with hope and QOL(all p's<0.05). Uncertainty revealed that there was a negative correlation among subitems of hope such as confidence, relationship with others, possibility of future, and inner motivation(r=-.333, p=.000; r=-.230, p=.015; r=-.260, p=.006; r=-.291, p=.003). Uncertainty also showed a negative correlation among subitems of QOL such as emotional status, self esteem, and relationship with family(r=-.29, p=.004; r=-.326, p=.000; r=-.197, p=.044), whereas hope revealed a positive correlation among subitems of QOL such as emotional status, self esteem, relationship with neighbor, and relationship with family(r=.243, p=.011; r=.487, p=.000; r=.29, p=.001; r=.29, p=.001). The score of uncertainty was low in graduate school students and subjects using problem solving as a coping method. However, the score of hope was high in college students and subjects using a problem solving method, and the score of QOL was high in professionals. Conclusion: Based on the study results, breast cancer patients experienced living with uncertainty and maintaining hope. Thus the study's findings can be useful in directing a comprehensive nursing care plan to improve QOL of breast cancer patients.