Fracture toughness is one of the most important mechanical properties for sheet metal in many applications. However not enough attention has been paid to the effects of laser forming conditions on fracture toughness of sheet metal. This paper presents an integrated fracture toughness model to study fracture toughness of sheet metal after laser forming. Microstructure, distribution of residual stresses and geometry of sheet metal specimen are considered in the model. Results of residual stress from microstructure-integrated finite element modelling of laser forming are incorporated in the model. Low carbon steel is used in this paper to validate the model. The results from the fracture toughness study are found to be consistent with microstructure analysis .