Gliomas are malignant primary brain tumors and yet incurable. Palliation and the maintenance or improvement of the patient’s quality of life is therefore of main importance. For that reason, health-related quality of life(HRQoL) has become an important outcome measure in clinical trials, next to traditional outcome measures such as overall and progression-free survivals, and radiological response to treatment. HRQoL is a multidimensional concept covering physical, psychological, and social domains, as well as symptoms induced by the disease and its treatment. HRQoL is assessed by using self-reported, validated questionnaires. Various generic HRQoL questionnaires, which can be supplemented with a brain tumor- specific module, are available. Both the tumor and its treatment can have a negative effect on HRQoL. However, treatment with surgery, radiotherapy, chemotherapy, and supportive treatment may also improve patients’ HRQoL, in addition to extending survival. It is expected that the impact of HRQoL measurements in both clinical trials and clinical practice will increase. Hence, it is important that HRQoL data are collected, analyzed, and interpreted correctly. Methodological issues such as selection bias and missing data may hamper the interpretation of HRQoL data and should therefore be accounted. In clinical trials, HRQoL can be used to assess the benefits of a new treatment strategy, which should be weighed carefully against the adverse effects of that treatment. In daily clinical practice, HRQoL assessments of an individual patient can be used to inform physicians about the impact of a specific treatment strategy, and it may facilitate the communication between the physicians and the patients. Gliomas are malignant primary brain tumors and yet incurable. Palliation and the maintenance or improvement of the patient’s quality of life is therefore of major importance. For that reason, health-related quality of life (HRQoL) has become an important outcome measure in clinical trials , next to traditional outcome measures such as overall and progression-free survivals, and radiological response to treatment. HRQoL is a multidimensional concept covering physical, psychological, and social domains, as well as symptoms induced by the disease and its treatment. by using self-reported, validated quesires. Various generic HRQoL questionnaires, which can be supplemented with a brain tumor-specific module, are available. Both the tumor and its treatment can have a negative effect on HRQoL. However, treatment with surgery, radiotherapy , chemotherapy, and supportive treatment may also improve patients’ HRQoL, in addition to extending survival. It is expected that the i mp, of the HRQoL measurements in both clinical trials and clinical practice will increase. Therefore, it is important that HRQoL data are collected, analyzed, and interpreted correctly. Methodological issues such as selection bias and missing data may hamper the interpretation of HRQoL data and should therefore be accounted. In clinical trials, HRQoL can be used to assess the benefits of a new treatment strategy, which should be weighed carefully against the adverse effects of that treatment. In daily clinical practice, HRQoL assessments of an individual patient can be used to inform physicians about the impact of a specific treatment strategy, and it may facilitate the communication between the physicians and the patients.