An emissions study for arsenic was conducted at a 300 MW coal-fired plant equipped with an electrostatic precipitator. The input and output streams such as coal, slag, ESP ash, and flue gas containing the post-ESP particulates were collected. Gaseous arsenic was sampled using EPA method 29 and the arsenic concentrations in the samples were measured using inductively coupled plasma atomic emission spectrometry (HG-ICP-AES). The mass balance recovery of arsenic estimated in this study was 87.2%. Arsenic concentration in stack gas was 2.5 microg/m3. Approximately 0.53% of the coal-derived arsenic was incorporated into slag, 84.6% of the arsenic was found on the fly ash collected by electrostatic precipitators, and 2.16% was found in the vapor phase. The relationship between arsenic concentration and ash particle size was also assessed, and arsenic is significantly concentrated in the small sized particles.