To report treatment times (door to door) of adjuvant treatments of breast cancer (BC) with intensity-modulated radiotherapy (IMRT).Treatment times of 62 patients with BC on the TomoTherapy Hi-Art System were collected for the analysis. Patients underwent either locoregional radiotherapy (postmastectomy radiotherapy [PMRT]) with helical modality (TomoHelical) or whole breast radiotherapy (RT) with simultaneous integrated boost (WBRT-SIB) with direct modality (TomoDirect). Door-to-door time was broken down into different steps, which were crucial to RT session.A total of 594 treatment fractions were monitored. Median treatment time was 22.4 minutes (17.2-30.8) for PMRT and 14.4 minutes (10.9-23.5) for WBRT-SIB. The mean beam-on time accounted for 61.36% of the overall treatment time for PMRT compared to 57% for WBRT-SIB. The beam-on time was a much more time-consuming process.This treatment times analysis on the use of IMRT for BC might be useful to organize and improve the workflow efficiency in RT facilities.