BACKGROUND : Breast cancer arises from the luminal epithelial cells. Myoepithelial cells (MEC) maintain tissue polarity and form natural borders separating the luminal epithelial cells from the surrounding stroma. This anatomical relation suggests that MEC might inhibit the progression of in-situ to invasive breast carcinoma. In breast cancer progression, the fully differentiated myoepithelial cells gradually disappear. Therefore, identification of MEC by immunohistochemistry serves as a valuable tool in assessing the various stages of progression of breast cancer. AIM AND OBJECTIVES : To study the various expression patterns of myoepithelial cell differentiation markers like p63, Calponin and smooth muscle actin (SMA) in patients with normal breast, usual ductal hyperplasia, ductal carcinoma in-situ (DCIS), DCIS with microinvasion and invasive ductal carcinoma and to determine the sensitivity and specificity of these markers. MATERIALS AND METHODS : A total of 75 cases were included in the study and were segregated into five groups with each group consisting of 15 cases. Immunohistochemical testing for p63, calponin and smooth muscle actin (SMA) was done manually. Chi Square test was done to assess the sensitivity of the markers. RESULTS : p63 was expressed more frequently than calponin and SMA. Expression of p63 was seen in 49 cases (65.33 %), calponin in 41 cases (54.66 %) and SMA in 32 cases (42.66 %). Strong intensity was observed with p63. CONCLUSION : p63 is more reliable and sensitive when compared with other myoepithelial cell markers. But a cocktail of markers is recommended in critical cases. The various staining patterns enhance our knowledge on tumor biology and improve diagnostic and therapeutic strategies for patients with breast cancer.