ABSTRACT. -This article gives Bohr-Sommerfeld rules for semiclassical completely integrable systems with two degrees of freedom with non-degenerate singularities (Morse-Bott singularities) under the assumption that the energy level of the first Hamiltonian is non-singular. The more singular case of focusfocus singularities was treated in previous works by San Vũ Ngo . c. The case of one degree of freedom has been studied by Colin de Verdière and Parisse.The results are applied to some famous examples: the geodesics of the ellipsoid, the 1 : 2-resonance, and Schrödinger operators on the sphere S 2 . A numerical test shows that the semiclassical Bohr-Sommerfeld rules match very accurately the "purely quantum" computations. Les résultats sont appliqués à quelques exemples célèbres : les géodésiques de l'ellipsoïde, la résonance 1 : 2 et les opérateurs de Schrödinger sur la sphère S 2 . Un test numérique montre que les règles de BohrSommerfeld semi-classiques sont en parfait accord avec les calculs "purement quantiques". 2003 Éditions scientifiques et médicales Elsevier SAS