The cointegration and GARCH models are the two most successful applications in macroeconomic econometrics, but only few researchers attempt to integrate these two popular models. This paper introduces a single equation cointegration model with GARCH(1,1) disturbances. Maximum likelihood estimators and their asymptotic distributions are derived for the parameters in the equation, in which the estimator of the cointegrating coefficient is asymptotically mixed and normally distributed. Empirically, we employ the model to examine Taiwan stock indexes and the associated futures prices of daily stock market data. The resulting estimates show that index futures and spot indexes are indeed cointegrated, and that the disturbances also exhibit a strong GARCH effect.