['The Ki67 labeling index (LI) reflects the proliferative activity of breast cancers and defines luminal A and B tumors; however, no detailed method to measure Ki67 has been standardized. Here, we propose a fast and easy way to evaluate Ki67.', 'Immunohistochemical staining of estrogen receptor (ER), progesterone receptor (PgR), HER2 and Ki67 (MIB-1) was performed on 235 primary invasive ductal carcinomas. For each sample, a hot spot with many Ki67+ cells was identified using a low-power field (40×, 4× objective). Three independent areas in high-power field (400×) were selected at the hot spot, and all cancer cells in the 3 areas were manually counted to calculate LI (% Ki67+ cells). Alternatively, micrographs taken at 100× and 200× fields including the hot spot were shown to 2\xa0pathologists, who visually assessed percentages of Ki67+ cells in 10\xa0% intervals at a glance (Eye-10).', 'Eye-10 and LI were strongly correlated (r\xa0=\xa00.9412, P\xa0<\xa00.0001). All cases of Eye-10\xa0≥\xa030\xa0% had LI\xa0>\xa014\xa0%; most of those <10\xa0% had LI\xa0<\xa014\xa0%. Of 170 ER+/HER2- tumors, Eye-10-based subtypes matched 87\xa0% of LI-driven subtypes, and interobserver agreement was good (κ\xa0=\xa00.705).'] Is visual assessment of Ki67 at a glance an easy method to exclude many luminal-type breast cancers from counting 1000 cells?