In order to characterize very local energy dissipation during crack propagation in polymers, an ultramicrotome was instrumented to measure the energy dissipated during sectioning. The work to section per unit area, W-s, was measured for five different amorphous polymers [polymethyl methacrylate (PMMA), polystyerene (PS), polycarbonate (PC) and two epoxy resins] in the glassy state. When the section thickness was varied between 60 and 250 nm, Ws varied between 15 and 100 Jm(-2), depending on the material and section thickness. The method and the results are compared with other methods used for determining the energy dissipation at a local level as well as at a macroscopic level in polymers. The differences between different polymers were found to be contradictory to macroscopic fracture toughness, G(Ic), measurements. The material that showed the highest W-s had the lowest G(Ic), values reported. Possible mechanisms for energy dissipation during sectioning are also discussed.