The present study examines dynamic relation between stock index and exchange rate by using the daily data for India. The empirical evidence suggests that there is no long-run relationship; however, there is bidirectional causality between stock index and exchange rates. The findings of the causality tests strongly support portfolio or macroeconomic approach on the relationship between exchange rates and stock prices. An attempt is also made to forecast daily returns of INR/USD exchange rates by exploiting the information of causal relationship between exchange rates and stock index using Vector -of-sample performance is benchmarked against the traditional ARIMA model. The potential of the two models is rigorously evaluated by employing a cross-validation scheme and statistical metrics like mean absolute error, root mean square error and directional accuracy. Out-of-sample performance shows that VAR model is robust, and consistently produces superior predictions than ARIMA model.