The aim of this paper is to investigate on the effectiveness of the liquidity effect of monetary policy actions in the CEMAC region. As the conventional wisdom states, a cornerstone for the central bank to stimulate the economy is to lower interest rates by increasing the supply of narrow money. To circumvent some of the difficulties inherent to the verification of this assumption, we adopt in this study, a methodology advocated by Christiano and Eichenbaum(1991) which seems appropriate in the special case of the CEMAC countries. The results we obtain indicate that the conventional wisdom holds both on individual level and on a regional basis when the monetary aggregate measures the stance of monetary policy. Moreover, an unanticipated credit expansion causes the interest rate to decline in most of the CEMAC countries. However, both the liquidity effect and the loanable effect are offset most of the time by a price puzzle or an output puzzle. In some countries, there is also an evidence of a liquidity puzzle. On the other hand, identification assumptions based on the interest rate are unsuitable for an appropriate assessment of the liquidity effect in the region.