Background & Aims: Breast cancer is the most common cancer in woman which includes 25% of all cancers in woman.

Biopsy is the gold standard method for diagnosis of breast messes but since about 70% of the breast masses are bengin, non-invasive diagnostic methods including FNA are more useful and important. Here we decide to compare the results of FNA with biopsy of palpable breast masses in patients referred to Imam-Reza hospital , Kermanshah.

Materials & Method: All the selected patients (58 patients) with palpable masses referring with biopsy were selected, and FNA were performed. Then smears were stained with pap and Gaimsa methods and were reviewed by two pathologists, separately.

Results: FNA was done on 58 patients with median age of 40.82±12.8 years .The results of cytologic diagnosis and pathologic study were comparable for the first and second pathologist in 78%(kappa:0.59) and 86%(kappa79%), respectively. Percent of agreement of FNA cytologic diagnosis for two pathologist was 86%.Sensitivity, specificity, positive predictive value and negative predictive value was 77.23, 91.12, 88.64, 83.54 and 85%, respectively.

Conclusion: It appears that FNA is an essential method for diagnosing breast masses and this test is a complementary method. Meanwhile, FNA for diagnosis is more powerful when it is accompanied by radiological and clinical data.