Small punch testing was carried out on Copper-Chromium-Zirconium alloy subjected to two heat treatment conditions –both quenched and one subjected to subsequent aging. The variation in the load displacement characteristics associated with the testing was attributed to differences in plastic and damage properties evolved as a consequence of these two varying heat treatments. The influence of these properties varied in different regimes of the load-displacement curve. In this work the elastic and plastic properties derived from uniaxial tensile tests performed on materials subjected to these two heat treatment conditions were used to simulate the initial stages of the load displacement curve. Using an inverse finite element method, the parameters relevant to a Gurson-Tvergaard-Needleman based damage model which influence the later stages of the load-displacement curve were estimated. The variations in the damage model’s parameters with respect to heat treatment conditions were correlated with fractographic observations.