The present study has as its theme the problem of the fight against money laundering by the Congolese banking system, to explain this phenomenon, we have based ourselves on the literature relating to money laundering and the banking system. To this end, we formulated our research question as follows: Are the international provisions concerning the fight against money laundering applied by Congolese banks? If not, what are the explanatory factors? Given the questions raised in the problematic, we have put forward the following hypotheses:- The international provisions concerning the fight against money laundering by Congolese banks can be explained by several factors, including:- the fact that the Congolese economy is essentially based on cash payments,- the fact that the Congolese economy is largely informal,- the permeability of Congolese borders, the permeability due to the high degree of corruption and the fragility of state institutions fueled by wars, insecurity etc.