BACKGROUND: In intracranial tumors, glucocorticoids are the main therapy to treat peritumoral edema. Neurologic Assessment in Neuro-Oncology (NANO) score is an instrument that can assess neurological function objectively and practically in patients with intracranial tumors. AIM: This study aims to determine the effect of dexamethasone administration on the NANO score of intracranial tumor patients. METHODS: This study was a pre-experimental study with a pre and post-test design at the H. Adam Malik General Hospital in Medan from March to September 2020. The study population was intracranial tumor patients. The research subject were 37 subjects taken consecutively. Treated with dexamethasone injection, then examined the NANO score before and after receiving dexamethasone injection on days 1, 2, and 3. Statistical analysis with Friedman test. RESULTS: Based on the demographic characteristics of the research subjects, the mean age was 53.29 ± 8.5 years. Most of the research subjects were male (54.1%) while female (45.9%). Most types of intracranial tumors were secondary tumors (59.5%) while primary tumors (40.5%). The significant effect of dexamethasone on NANO score in patients with intracranial tumors (p < 0.001). CONCLUSION: There is an effect of dexamethasone on the NANO score of patients with intracranial tumors.