The deposition of suspended iron oxide in water at a 10-atm pressure during nucleate boilings on a Zircaloy heated surface has been studied. The effects of pressure on the deposition rate during the initial period have been investigated. The previously proposed iron oxide deposition model, based on the microlayer evaporation and dryout phenomena that occur in the nucleate boiling bubble at atmospheric pressure, is extended to high-pressure nucleate boiling conditions. The model is shown to be applicable for high-pressure studies.