OBJECTIVE To determine frequency of triple negative breast cancer (TNBC) in Pakistani women with respect to age. STUDY DESIGN Observational study. PLACE AND DURATION OF STUDY Armed Forces Institute of Pathology (AFIP), Rawalpindi, from July 2005 to July 2010. METHODOLOGY Pathological records of all specimens of breast cancer were reviewed and data was obtained for estrogen receptor (ER), progesterone receptor (PR) and HER-2 neu receptor proteins. Specimens having complete record of all three proteins were included for analysis. TNBC was defined as those who were ER, PR and HER-2 neu negative. Overall frequency as well as frequency with respect to age was calculated. Descriptive and categorical variables were analyzed using SPSS version 17. RESULTS Eight hundred and fifteen patients out of 4715 (17.28%) were found to be TNBC. Mean age of diagnosis of TNBC was found to be 46.26 ± 12.22 years of age while other breast cancers had a mean age 52.90 ± 9.78 years (p < 0.001). In the TNBC group, 537 patients (65.88%) were aged < 50 years while 278 patients (34.11%) were aged > 50 years while majority of patients with other breast cancers were elderly females (p < 0.001). CONCLUSION TNBC comprised 17.28% of the breast cancers in Pakistani women diagnosed at the studied centre. A higher frequency of TNBC was noted in significantly younger patients.