This study examined the relationship between the 6-min walk test (6MWT) and fitness, psychological and physiologic states, quality of life, cancer-related symptoms, and body composition of 87 women with breast cancer. The assessment included the 6MWT and evaluations of Cancer Quality of Life (EORTC C-30 and EORTC BR-23), cognitive performance (Trail Making Test), the Hospital Anxiety and Depression Scale, body composition, health-related fitness (abdominal test, multiple sit-to-stand test, trunk dynamometry), and pain (Brief Pain Inventory). We observed the following correlations: moderate between 6MWT and pain interference; modest for cognitive and social functioning and the multiple sit-to-stand test; fair for several items on the Cancer Quality of Life, for anxiety, lean body mass, trunk dynamometry and pain intensity; and weak for role functioning, loss of appetite, cognitive performance and depression. Thus, the 6MWT could be used as a measure of the major components of global health in women with breast cancer.