In this paper we will analyze the impact of credit risk in bank performance, precisely SociétéGenerale Congo.Societe Generale Congo came in Republic of Congo during a critical period of　　the economy caused by the fall in oil prices but was able to take off.Although the profits are still negative but the evolution is quite significant.Our work has shown that during these two years the credits granted have increased considerably, as well as operating costs; but this didnot prevent the banks profitability from rising.This may explain a fairly good management at SGC.We conducted our work by presenting the credit risk study and its evaluation at SGC as well as astatistical study using the profitability criteria of the bank.