Digital breast tomosynthesis (DBT) is a new imaging technology that addresses the limitation caused by overlapping structures in conventional two-dimensional digital mammography owing to the acquisition of a series of low-dose projection images. This unique technique provides a dual benefit to patients screened for breast cancer. First, DBT increases the cancer detection rate mostly by highlighting architectural distortions and allowing better assessment of masses shape and margins. Second, DBT helps reduce recall rate by discarding asymmetries related to overlapping tissue. However, DBT is not included in the majority of cancer screening programs worldwide. Several issues still need to be addressed such as over-diagnosis and over-treatment, lack of reduction of interval breast cancer, quality control and storage, and radiation dose. In the diagnostic setting, DBT increases the diagnostic accuracy and reduces the number of indeterminate lesions in symptomatic women. Its aforementioned performances regarding asymmetries, masses and architectural distortions allow reducing the number of additional views while working-up a screening-detected lesion. Tumor size is also better assessed at DBT as well as multicentricity, two significant benefits in the staging of breast cancer. Finally, DBT allows a better analysis of scars and helps reduce the rate of indeterminate findings after surgery. Although somewhat limited by high breast density, DBT globally outperforms digital mammography in both screening and diagnostic breast imaging. Additional research is however needed, particularly on relevant screening outcomes. This review describes the main performances of breast DBT in breast cancer screening and diagnosis and the resulting consequences in both settings.