Orthotropic composite materials exhibits higher specific strength and stiffness; hence extensively used in various industrial and engineering applications such as aerospace, armored and automobile etc. During their service life, these critical engineering components are subjected to thermo-elastic loads. These loading conditions generate local thermal stress concentration near the crack/voids present in the structures, which leads to sudden failure of engineering components. Therefore, the study of crack tip stress field under thermo-elastic loading becomes very important to understand the effect of lamina orientation on the strength of orthotropic composite components. The presented work deals with XFEM formulation and implementation to simulate 3-D orthotropic fracture problems under thermo-elastic loading environment. In XFEM based formulation, meshed topology does not exhibit any geometrical discontinuity. All desired discontinuity can be captured by enriching primary variable approximations by additional mathematical functions (Heaviside and crack front enrichment functions). These enrichment functions are derived from theoretical background of the problem under consideration. The crack surface element enriched by Heaviside function whereas, crack front elements treated by orthotropic crack front asymptotic functions. Mixed mode stress intensity factors are computed by domain based interaction integral approach. Few example of 3-D orthotropic thermo-elastic crack problem is presented to illustrate the effectiveness and robustness of proposed method. © 2015 AIP Publishing LLC.