This study investigates whether the capital market values the efficiency of firms. After tracing stock returns and efficiency changes of 399 listed insurance firms in 52 countries during the 2002-2008 period, the paper reports a positive and statistically significant relationship between profit efficiency change and market adjusted stock returns. However, there is no robust evidence that cost efficiency change is associated with stock returns. Keywords: Efficiency, insurance, stock returns. JEL: C22 C34 G22