Background: The first random study of incidence of Her-2 over expression among Omani breast cancer patients was carried out by the Medical Oncology Department, the Royal Hospital in 2001. The incidence was reported as 40% (higher than international published figures). The Herceptest was routinely performed on all new patients for a whole year (2004) and the incidence was found to be 36%. Trastuzumab was approved for use in the Sultanate of Oman in 2002, since then a total of 26 patients with metastatic breast cancer received Trastuzumab, the results are presented. Methods: Prospective, single arm, single centre experience. Patients with confirmed metastatic breast cancer (at presentation or after adjuvant treatment), HER-2 positive (+++ by Herceptest, or FISH positive), age > 18, ECOG PS ≤ 2, LVEF = 50% and adequate renal & liver function, were included. Treatment consisted of …