In this work, Bézier extraction based extended isogeometric analysis (XIGA) has been performed for three-dimensional (3-D) crack simulations in linear elastic materials. The Bézier extraction represent the original NURBS basis functions in terms of Bernstein shape functions defined over C 0 continuous isogeometric Bézier elements, and provides an element wise data structure of NURBS which makes the implementation similar to extended finite element method (XFEM). A crack in the domain is modeled by Heaviside and crack tip enrichment functions. The values of mixed-mode stress intensity factors (SIFs) are obtained by interaction integral approach using virtual cuboidal domain. Various 3-D crack problems are solved by Bézier extraction based XIGA, and the results are compared with XFEM and analytical solutions.