Arsenic exposure in humans has been associated with adverse health effects such as neurological and cardiovascular effects, diabetes mellitus, skin lesions, skin, lung, kidney and liver cancers. Occupational exposure to arsenic usually occurs with inhalation of arsenic-containing particles in the mining industry. A simple and sensitive method was developed and validated for the determination of arsenic levels in biological samples by graphite furnace atomic absorption spectrometry (GFAAS), equipped with a Zeeman background correction system. Blood, urine, and hair samples are known to be the best biomarkers to assess arsenic exposure in humans. Samples were collected from 95 metal workers who were admitted at the Ankara Occupational Diseases Hospital in Turkey. Prior to analy sis, the samples were pre-treated with an acid digestion procedure. The method showed linearity in the range of 0-100 μg/L, with a detection and quantification limit of 0.37 μg/L and 1.1 μg/L, respectively. The calibration curve was characterized by a high correlation coefficient (r=0.9991). Validation of the method was performed in terms of precision and accuracy with the use of reference materials. The method was applied to the analysis of certified reference material samples with satisfactory results (96.77-97.50%). The arsenic levels of the biological samples of the metal workers ranged between 3.83-52.44 μg/L in blood; 1.26-27.54 μg/L in urine; and 0,06-7.90 mg/kg As in hair. The mean arsenic levels in the blood, urine, and hair samples of the silver metal workers were found at 21.25±12.47 μg/L. 6.43±4.99 μg/L, and 1.81±1.79 mg/kg As, respectively.