BACKGROUND: In postmenopausal women diagnosed with breast cancer (BC), most BC tumors are hormone receptor positive and guidelines recommend adjuvant endocrine therapy that includes an aromatase inhibitor (AI). This study investigates the impact of a 6-week, home-based, self-directed walking program on the commonly reported side effect of AI-associated arthralgia (AIAA). MATERIALS AND METHODS: In this phase II trial, consented BC patients were randomized to walking Intervention ( RESULTS: In our final sample ( CONCLUSION: This study adds to the growing evidence base suggesting exercise as a safe alternative or adjunct to medications for the management of AIAA. IMPLICATIONS FOR PRACTICE: Breast cancer survivors whose adjuvant endocrine treatment includes an aromatase inhibitor (AI) often experience the side effect of AI-associated arthralgia (AIAA). This study investigates the impact of a 6-week, home-based, self-directed walking program in the management of AIAA. Compared with Wait List Control, women in the Intervention group reported significantly increased walking minutes per week, reduced stiffness, less difficulty with activities of daily living, and less perceived helplessness in managing joint symptoms. This study adds to the growing evidence base suggesting exercise as a safe alternative or adjunct to medications for the management of AIAA.