This article summarizes the new response criteria of the Response Assessment in Neuro-Oncology (RANO) working group and the clinical implications. The RANO criteria represent an important step forward in the accurate assessment of response to therapy in patients with malignant gliomas, not only in clinical trials but also in daily practice. The introduction of new substances to glioma therapy, such as antiangiogenic drugs, has complicated the assessment of efficacy by MRI due to profound effects on the vascular biology of these tumors. Moreover new treatment modalities have increased the incidence and awareness of imaging phenomena, such as pseudoprogression and pseudoresponse, not only within clinical trials but also outside. In addition to MRI the new RANO criteria also take clinical parameters, such as steroid medication and neurological symptoms, into account. Thus both neuroradiologists and neurologists/neurooncologists need to be aware of and experienced in applying these criteria when treating patients with malignant gliomas to be able to correctly assess the response to therapy.