Recent regulatory changes imposed by the Environmental Protection Agency (EPA) and Occupational Safety and Health Administration (OSHA) concerning environmental emissions and worker exposure limits to chemicals have significantly impacted current chemical-based aircraft paint stripping operations. Pratt and Whitney Waterjet Systems is developing high-pressure water as an alternative technology to replace the current chemical process. A critical component for the high pressure water process is the nozzle assembly. Both commercially available and in-house designs of nozzle configurations have been extensively evaluated to select nozzles which meet stringent paint stripping requirements. This paper will present the results of the nozzle optimization work and the materials evaluations performed.