Interest rate uncertainty has adverse effects on stock market performance. Despite the considerable studies on the relationship between interest rate and stock market return, the relationship between interest rate volatility and stock market development still is enigma. This paper investigates the effect of interest rate uncertainty on stock market development. We examine the long-run and short-run relationship between these variables using Pesaran et al (2001) bounds testing approach to cointegration and error-correction modeling for 12 emerging economies over the period 1980-2011. This methodology has two main advantages over other cointegration methods which have made it unique: first there is no need to do pre-unit root resting, which is an essential requirement in other methods, and second, we are able to distinguish short -run effects from its long- run effect. Diagnostic statistics applied in this study indicate that our models are stable, well specified and normally distributed residual free of autocorrelation. The estimated results here show a significant short-run effect of interest rate uncertainty on stock market developing in all of 12 emerging economies under study. Furthermore, our results indicate that in 9 out of 12 countries the short-run effects have been seen in the long-run as well, and the cointegration relationship is confirmed in almost all of the models by either the F-test results or negative sign of error correction term. Also, the long run real income estimated elasticity is significantly positive in all countries (except for Brazil, Chile and Thailand) which would be a major long-run factor affecting stock market development in most of emerging economies in this study. Moreover, we found a mixed long- run effect of interest rate on stock market development. The results obtained in this paper suggest that emerging economies need to be cautious in implementing financial market and interest rate policies. A well-developed financial system improves capital formation and the efficiency of resource allocation, enhancing investment, and therefore economic growth. Interest rate uncertainty significantly affects stock market development. Therefore, a sound monetary policy creates a safer investment environment and stock market development. The role of stock market development towards achieving economic growth is crucial.