Abstract We investigate the extent of regional financial integration in the member countries of the Gulf Cooperation Council. Interest rate data show that convergence exists and that interest rate differentials are relatively short-lived—especially relative to other unified currency area and comparable to those of the Euro Area post 1999. Equity data using cross-listed stocks confirm that stock markets are fairly integrated compared to other emerging market regions, although price equalization is hampered by market illiquidity. The limited volume data available suggests that intra-GCC capital flows are sizeable.