The electrostatic potential distribution above the Pt(100), Pt(110) and Pt(lll) surfaces has been studied using finite cluster model representations of the surfaces and their ab initio Hartree-Fock electron densities. From the different distributions it is seen that electrostatic effects are not substantial for Pt(100), minor but significant for Pt(110) and quite important for Pt(lll). The minima of the electrostatic potential always appear at the more coordinated sites, four-fold for Pt(100) and Pt(110) and threefold for Pt(lll), indicating that, up to first order, electrophilic adsorbates will prefer to approach the high coordinated surface sites.