Alternating electrical fields can disrupt mitosis leading to apoptosis of rapidly dividing cancer cells. The device that utilizes this mechanism is known as tumor-treating fields (TTFields). TTFields can be applied by ceramic transducer arrays on a shaved scalp to deliver the alternating electric activity to patients with glioblastoma (GBM). It has FDA approval for use in both recurrent and newly diagnosed GBM. The objective is to critically appraise the current evidence for the use of TTFields as adjunctive treatment to newly diagnosed GBM. The objective was addressed through the development of a structured, critically appraised topic. We incorporated a clinical scenario, background information, a structured question, literature search strategy, evidence summary, clinical bottom lines, and expert discussion. Participants included consultant and resident neurologists, a medical librarian, clinical epidemiologists, and content experts in the field of neurooncology. A randomized controlled trial was selected for critical appraisal. Patients with newly diagnosed GBM completing standard radiation and chemotherapy with temozolomide (TMZ) were subsequently randomized to receive maintenance TMZ with TTFields, or TMZ alone. With the addition of TTFields, median progression-free survival was 6.7 months compared with 4 months without the addition of TTFields (95% confidence interval, 0.52-0.76; P<0.001) and overall survival was 20.9 months compared with 16.0 months without the addition of TTFields (95% confidence interval, 0.53-0.76; P<0.001). TTFields may increase both progression-free and overall survival in patients receiving standard chemoradiation therapy for GBM.