On the basis of raw return analysis, economically significant anomalies appear to exist in relation to the size, momentum, book-to-market and profitability of Australian firms. However, characteristic-sorted portfolios are shown to load in very particular ways on multiple risk factors. After adjusting for exposure to risk, convincing evidence only remains for the size premium. An analysis of seasonality shows that, rather than being consistent throughout the year, anomaly returns are concentrated in a handful of months. We provide and test preliminary explanations of the observed seasonality in these well-known anomalies.