The aim of this paper is to examine the impact of Information and Communication Technologies (ICT) on the growth of developping countries and especially on the Tunisian economy. The first part of the article summerizes the relationship between growth, productivity and ICT. We show that under some necessary conditions ICT may boost the growth in the developping countries. In the second part of the article, we estimate the contribution of ICT to the growth of Tunisia due to ICT diffusion and adoption. We compare our econometric estimation to the results obtained in France and United States.