<p>The analysis of rock tunnels can be significantly influenced by discontinuities, which affect their performance. However, evaluating discontinuous rock and crack propagation in tunnels using numerical methods poses certain challenges. The eXtended Finite Element Method (XFEM), when combined with fracture mechanics, offers a practical solution to these challenges. This study utilized XFEM to assess rock tunnel performance, accounting for both discontinuities and crack propagation. To achieve this, a custom XFEM program was developed in MATLAB to calculate displacements and stresses for a case study involving a tunnel within a discontinuous rock domain. Rock characteristics were determined through field investigations and laboratory tests to enhance the model’s accuracy. The validated program was then employed to analyze tunnel by modeling the discontinuous rock formation along the tunnel’s path under specific overhead loading conditions. The results were used to compare the maximum displacements of the tunnel both with and without accounting for discontinuities. The findings indicate that displacements and stresses calculated by XFEM for the model including discontinuities are approximately five times greater than those obtained for the model without discontinuities. This difference highlights the significant impact of geological discontinuities on tunnel response rather than a direct comparison between XFEM model and conventional FEM model. While the FEM model neglects cracks and layering, the XFEM framework enables their explicit representation, emphasizing the importance of incorporating geological heterogeneities into the modeling process.</p>