Human leukocyte antigen (HLA)‐F is one of the non‐classical HLA class I molecules that protects the fetus in pregnancy. HLA‐F expression was immunohistochemically examined and the association between clinical parameters and HLA‐F expression was analyzed. Cancerous HLA‐F and stromal HLA‐F‐positive infiltrating cells were detected in 91 (40.0%) and 186 (81.6%) cases, respectively. HLA‐F positivity in cancer cells was significantly associated with tumor size (P < 0.05). There was a weak correlation between HLA‐F positivity of cancer cells and HLA‐F positive infiltrative cells (P < 0.01, r = 0.11). HLA‐F positivity did not affect patients' survival in 209 breast cancer. However, confined to stage II breast cancer, the HLA‐F positive group showed significantly poorer outcomes than the HLA‐F negative group (P < 0.05). The present study provides the first evidence that HLA‐F positivity in breast carcinoma affects clinicopathological factors and could be selected as a prognostic marker for limited clinical stage.