Niobium has historically been utilized as an addition to nickel-base alloys for the purpose of strength enhancement, via both solid solution strengthening and precipitation hardening mechanisms. These phenomena are better understood than the effect that niobium addition exerts upon high temperature corrosion resistance. This study presents results of other studies as well as data obtained in-house. The effect of niobium addition upon corrosion behavior in oxidizing and oxidizing-sulfidizing environments will be explored. In addition, the effect of niobium addition upon material performance in a simulated waste incineration environment will be examined. Mechanisms governing observed behavior will be proposed and discussed.