In order to examine association patterns and pollution potential of trace and major elements from coal ash, six composite samples of fresh, filter fly, and aged dump coal ash from "Kostolac A" power plant located 100 km from Belgrade, the Serbian capital, were subjected to the sequential extraction procedure. Five extractants were applied (in the following order): distilled water, 1 M ammonium acetate, 0.2 M ammonium oxalate/0.2 M oxalic acid, an acidic solution of H2O2, and 6 M HCl. Obtained concentrations were statistically analyzed and associations of trace and major elements were established.