The objective of this effort was to evaluate and model the effects of moisture, temperature, and combined hygrothermal aging on the strength and life of a graphite/epoxy woven composite material system. The material system studied is a candidate for use in an advanced subsonic aircraft engine, and the imposed environmental and aging conditions were considered to be representative of the engine service conditions. Fatigue and residual strength data showed that initial and residual tensile properties and fatigue life of the material were only minimally affected by any of the imposed environmental conditions. However, fatigue damage progression and accumulation were found to vary with temperature and with different fatigue stress levels. Because of the lack of environmental effects on the residual strength data and life of the material, room temperature data were used in a residual strength based life prediction approach to model with reasonable results.