Following the recent financial crisis there has been a huge increase in research on liquidity related topics both with respect to macro liquidity, funding liquidity, the liquidity of different asset classes and markets as well as the flow of funds between different assets and markets. The main objective of this research is to examine the bidirectional effects of the Egyptian Stock Exchange liquidity, and the Egyptian business cycle. This research depends upon the deductive approach which starts with generalities, after admitting its soundness, and ends up with particulars using the logical analysis to predict some findings of the hypotheses under study. This approach attempts to use specific theories in the interpretation of phenomena discovered by the researcher, and that's by reviewing previous studies, formulating some testable hypotheses and then collecting data to test hypotheses using statistical methods. The results of multiple regression and event study analyses shows that trading volume growth has a significant positive effect on real GDP growth. Also, real GDP growth has a significant positive effect upon market capitalization growth and bid-ask spread growth. This ensures that there are bidirectional effects between the Egyptian stock market liquidity and the Egyptian business cycle. The main contributions of this study are twofold. Firstly, the bidirectional effects of stock market liquidity and the business cycle is still puzzling, and not conclusive around the whole world. Secondly, this is the first time, to the best of his knowledge, to conduct a research about these effects in Egypt; which has the biggest and oldest Stock Exchange in the Arabic area.