Craze growth in a styrene-acrylonitrile copolymer (SAN) was studied as a function of time after a quench (physical aging) at four different temperatures between 22 and 60°C. The craze growth experiments were performed in stress relaxation conditions. The craze length was found to grow linearly on a logarithmic loading time scale. A transition in the logarithmic growth rate was found to occur on the logarithmic aging time scale. The transition was observed as a change in rate from high to approximately five times slower and occurred over a relatively narrow range of aging times. The growth rate in the slow growth regime was relatively insensitive to temperature for all four temperatures studied. The transition was found to move to shorter aging times as temperature increases. Although the craze length between crazes in a sample could differ to a large extent, the growth rates themselves, were found to vary only within a ±20% band.