Awake surgery with intraoperative brain mapping is highly recommended for patients with diffuse low-grade gliomas in language areas, to maximise the extent of resection while preserving the integrity of functional networks and thus quality of life. The picture-naming test "DO.80" is the gold standard for language assessment before, during, and after surgery. Cognitive functioning is correlated with quality of life, itself linked with return to work. Our objective was to evaluate the significance of measuring naming speed, and its correlation with the return to professional activities. Two complementary studies are reported. In the first retrospective study, eleven patients were examined post-operatively. Five patients were selected because they were not able to resume their professional activities ("no return group 1"). They were compared with a control group of six patients who are working normally after surgery ("return group 1"). The eleven patients performed a global language and neuropsychological assessment, with a post-operative median follow-up of 35 months. In a subsequent prospective study, twelve patients were examined pre-operatively and post-operatively. Six patients who were not able to return to work ("no return group 2") were compared with a control group of six patients who were working normally after the surgery ("return group 2"). The twelve patients performed a pre and post-operative language assessment, with a median follow-up of 9 months. Our results show, for the first time, that naming speed is significantly correlated with a major criterion of quality of life: the return to professional activities. There were no differences between the two groups regarding other measures of cognition. Assessing naming times, and not only naming accuracy, is essential in the management of low-grade glioma patients, before, during, and after surgery, to preserve their quality of life by resuming their previous professional activity. Our results have fundamental implications concerning the comprehension of language processing and its relationship with cognitive functioning.