The aim of this paper is to empirically analyze the effect of financial constraint, information asymetry on the firm investment. On the basis of a data relating to 394 Tunisian firms observed over the period 2001-2008 and by adopting the panel data method, our findings show that the effect of financial constraints varies according to the number of bank-firm relations, the funding mechanisms and the investment type. | Financial constraints, information asymmetry and Tunisian firm investment