A series of pilot scale incineration tests were performed at EPA's Incineration Research Facility (IRF) to evaluate the fate of arsenic when fed to a rotary kiln incinerator. In addition to parametric tests, an arsenic-containing soil from a Superfund site was also fed to the same incinerator. The operation of the incinerator and the resulting test conditions were similar. The data showed that arsenic when incinerated tends to partition to the bottom ash. However, as the temperature in the kiln rises, the amount of arsenic partitioning to the ash decreases. With regard to the Superfund soil, the TCLP values for arsenic went down as the oxygen level in the kiln increased. Afterburner temperature and chlorine concentration in the waste did not appear to have any effect on the partitioning of arsenic.