Background and Objectives: Breast carcinoma, the most common malignant tumor and the leading cause of cancer death in women, affects Iranian women at least one decade earlier. Lymphatic vessel invasion (LVI) is one of the most important prognostic factors in breast carcinoma. The aim of this study was to compare the results of detecting lymphatic invasion in immunohistochemistry (IHC) method with routine histologic evaluation. Materials and Methods: A total of 116 breast cancer specimens were evaluated. IHC staining for D2–40 marker was performed on paraffin‑embedded blocks of tumor samples to detect LVI. Results: Sensitivity, specificity, positive, and negative predictive values of H and E staining for detection of the lymphatic invasion were 41%, 66%, 54.8%, and 53.5%, respectively. Kappa coefficient between H and E and D2–40 stainings was 0.078. The most common sites of lymphatic invasions were intratumoral area and tumor periphery. Conclusions: It seems that D2–40 staining is necessary for accurate diagnosis of LVI in breast cancer. Furthermore, evaluation of intratumoral area and tumor periphery can probably increase the chance of finding lymphatic invasion.