Thermoplastic elastomers are a class of engineering materials that can replace conventional vulcanized elastomers in several applications such as: seal rings, membranes, wear goods. In these and other applications, the capacity to resist crack propagation, especially when they operate under cyclic conditions, is crucial to define TPE’s life time. The high viscoelastic character, the strong effect of processing conditions and temperature on their microstructure have been extensively studied but a similar study on fracture and cyclic fatigue is still missing for this class of materials. We report values of fracture toughness for two commercial soft thermoplastic polyurethanes (TPU) and compare them with those obtained in cyclic fatigue at different temperature. The obtained results are quite unexpected and sometimes tough to relate to monotonic properties of two polymers.