The aim of this study was to estimate the hospitalization and ambulatory costs related to breast cancer due to physical inactivity in the female population from Brazilian capitals over a three-year period (2015 to 2017). This study was carried out with data from the Brazilian health system and had as metrics incidence of breast cancer, total and standardized rate hospitalizations by breast cancer, hospitalization and ambulatory costs by breast cancer and prevalence of physical inactivity. The Population Attributable Fraction (PAF) calculation was used. The total hospitalization cost by breast cancer in women aged ≥ 20 years in Brazil from 2015 to 2017 was US$ 33,484,920.54. Of this total, US$ 182,736.76 was due to physical inactivity. Outpatient expenses related to breast cancer in the Brazilian female population from 2015 to 2017 was US$ 207,993,744.39. Of this total, US$ 1,178,841.86 was due to physical inactivity. Outpatient and hospitalization expenses were higher in the states of Southeastern, Southern and Northeastern regions. Physical inactivity has contributed to the high number of hospitalizations for breast cancer in Brazil, which resulted in economic burden for health services (inpatient and outpatient) of more than US$ 1,300,000.00 from 2015 to 2017.