One of the main aims of awake surgery for glioma patients is to preserve quality of life, while maximizing tumor resection. Focusing on an important yet understudied aspect of quality of life, this thesis investigates to what extent written language may be affected by a glioma or glioma surgery. By reviewing current assessments of reading and spelling in awake surgery studies, we aimed to provide a better understanding of how neuroanatomical theories may guide neurosurgical practice, and to evaluate how examinations of written language in glioma patients can be improved. To provide a direct clinical application for this knowledge, we developed a theory-driven written language battery specifically for glioma patients. Lastly, we tested its efficacy and evaluated reading and spelling performance in neurosurgical practice. The studies in this thesis have provided a better understanding of written language in neurosurgical practice. In particular, it has contributed to prediction and prevention of written language disorders in glioma patients undergoing awake surgery, and it has resulted in a valid examination tool to carefully monitor reading and spelling in this patient group.