Mercury capture on fly ash was studied at a coal-fired utility boiler burning a single-mine source high-Hg Appalachian coal. Other elements were also studied incidental to the Hg study. Fly ash was collected through a cross-section of the ash collection system, representing ash captured at different flue gas temperatures. In general, Hg concentration in the fly ash increases with an increase in the fly ash carbon and a decrease in flue gas temperature. The relationship between the latter two parameters and the Hg content was not as well defined as in previous studies where the petrographic forms of the carbon could be isolated.