PurposeIn Chilean patients with breast cancer (BC) receiving chemotherapy we aimed to (a) report the levels of physical activity (PA), (b) compare clinical/socio-demographic parameters among patients with different levels of PA, and (c) explore exercise preferences.MethodsPatients (n=112) completed a questionnaire regarding their PA habits, and another questionnaire regarding their preferences for an exercise program. Patients were then divided into three groups based on the exercise guidelines for patients with BC (150min/week of moderate exercise, or 75min/week of vigorous exercise). The groups were (i) not engaging in any moderate-to-vigorous PA (MVPA), (ii) engaging in some MVPA, but not meeting the guidelines, and (iii) meeting the guidelines. Clinical/socio-demographic parameters and preferences for exercise were compared between groups.ResultsOnly 13% of patients with BC met the exercise guidelines. These patients were younger, had been diagnosed more recently, and had fewer children than patients not engaging in MVPA. There were no differences in the preferences for exercise between groups. Overall, patients preferred to exercise with other patients (76%), at moderate intensity (67%), performing different activities (94%), supervised (94%), with a fixed schedule (69%), and to do group activities (90%).ConclusionMost patients with BC receiving chemotherapy did not meet the exercise guidelines. Patients >50years old and with >2 children were the most inactive. Efforts to increase PA levels should focus especially on these patients. The preferences for exercise reported here will help to increase adherence to exercise programs and improve outcomes for these patients in Chile.