In this paper, the effect of aging on the ignitibility and reproducibility of a composite solid propellant was investigated. Ignition delay times of solid propellant samples undergone different degrees of aging were determined under various levels of incident CO2laser energy fluxes. Micrographs obtained from an Environmental Scanning Electron Microscope (ESEM) showed that the surfaces of the aged samples exhibited fiber-like structure as compared to the heterogeneous structure of the as-machined sample. The porosity of the fiber-like structure increased with the degree of aging. Based upon the results of experiments, it was observed that aged propellant samples require much longer heating time to reach self-sustained combustion condition than the as-machined sample at lower energy fluxes (around 50 W/cm2). However, at higher energy fluxes (around 150 W/cm2), the effect of aging on the ignition delay times became smaller.