The Molasse is a geologic formation which covers most part of the Swiss plateau. This sedimentary formation is constituted by various types of rock such as sandstones, marls (claystones) and siltstones. The Rock Mechanics Laboratory (LMR) of the EPFL has a great number of test results (uniaxial, triaxial and Brazilian tensile strength) on various types of Molasse. The obtained results related to the lithological characteristics of this formation were statistically analyzed in order to define correlations between the different mechanical properties of these rocks. The parameters of the failure strength criteria according to Hoek-Brown and Mohr-Coulomb have been estimated for different components of Swiss Molasse.