OBJECTIVES: To compare lean mass, fat mass, and bone mineral density (BMD) in the affected arm (the arm on the side where breast cancer was present) and unaffected arm of breast cancer survivors without lymphedema. SAMPLE & SETTING: 38 breast cancer survivors who had completed primary treatment were included in this analysis at a university in Florida. METHODS & VARIABLES: Arm lean mass, fat mass, and BMD were obtained using dual-energy x-ray absorptiometry. Paired t tests were used to compare tissue composition and BMD between the affected and unaffected arm. Independent t tests were used to compare interlimb differences between those participants whose affected arm was on the dominant and those whose affected arm was on the nondominant side. Significance was accepted at p < 0.05. RESULTS: The affected arm had lower fat mass and BMD as compared to the unaffected arm. Differences in lean mass were not statistically significant (p = 0.06). In breast cancer survivors whose nondominant arm was affected, lean mass, fat mass, and BMD were significantly lower in the affected arm. IMPLICATIONS FOR NURSING: The results show that the affected arm of breast cancer survivors is susceptible to negative tissue and BMD changes. This highlights the importance of educating individuals with breast cancer about these changes and supports the benefits of upper body resistance training.