ABSTRACT The impact of intellectual capital on firm performance is still poorly defined. In this paper, we try to find the relationship between intellectual capital and business performance from the standpoint of financial performance, the marketplace and economics. We conduct a study of the literature on this subject and we announce our research hypotheses. Our empirical study use a sample of 25 companies listed on the stock market in Tunisia. By using a panel’s data we perform the necessary tests for obtaining robust results. The main objective of this study is to determine an exact impact of intellectual capital on the performance of these companies. Keywords: intellectual capital, performance, panels, Tunisia, relationship.