The relationship between pain and quality of life (QOL) in cancer patients is complex due to the number and the diversity of factors that can influence pain and QOL. The aims of this study of oncology outpatients with pain from bone metastasis were: 1) to determine the extent to which pain characteristics (i.e., severity, duration, meaning of pain, and perceived availability and efficacy of pain relief), psychological distress (i.e., depression), physical functioning, social functioning and QOL are intercorrelated, and 2) to determine which of these variables are important predictors of QOL. A total of 157 oncology outpatients completed questionnaires that evaluated pain, QOL, depression, physical functioning, and social functioning at the time of enrollment into a randomized clinical trial that evaluated the effectiveness of a psychoeducational intervention to improve cancer pain management. Pearson product moment correlation coefficients were calculated to examine the relationships among the study variables. A blockwise, hierarchical multiple regression analysis was performed to determine which variables were the most important predictors of QOL. Meaning of pain was significantly correlated with all the other variables, in particular pain intensity and duration. The most important factors that predicted QOL were depression, social functioning, and physical functioning. Depression proved to be the most important predictor of QOL.