Mode I crack propagation in prestressed concrete sleepers B70 is simulated by a fracture mechanics approach. The plastic damage model, which takes the non-linear behavior of concrete into account, is utilized to calculate crack length and crack mouth opening displacement (CMOD). Numerical data from prestressed concrete sleepers B70 under three-point bending load are compared with those of the proposed fracture mechanics model. In this study, fracture mechanics parameters of prestressed concrete sleepers are investigated. Sleepers with the length of initiation crack of 5 mm and a 10 mm step increasing to 45 mm and the width of initiation crack of 2 mm with a 2 mm increasing to 8 mm are analyzed. Sleeper cracks are created in the notch and both of its sides. These analyses confirm that the structural behavior of prestressed concrete sleepers can be predicted by a simple fracture mechanics model provided that the related material properties like KIC, crack length and CMOD, are known.