The use of leasing and/or bank lending has always generated a very rich and controversial debate in the economic literature. It is generally accepted that leasing is a complement and not a substitute for bank lending in corporate finance. In this thesis, we will study the impact of leasing and/or bank credit on the activity of Congolese companies. To do so, we use the binomial logit model to identify the factors that explain the use of bank credit and/or leasing. Findings from our results show that companies use bank credit more than leasing.