The 2017 American Academy of Neurology (AAN) guideline on mild cognitive impairment (MCI) has been published recently. The guideline panel systematically reviewed literatures on MCI prevalence, prognosis, and treatment according to AAN evidence classification criteria and provided recommendations based on the evidences. MCI prevalence increases with age. Individuals with MCI are at higher risk of progressing to dementia than age-matched controls. No high-quality evidence exists to support pharmacologic treatments effective for MCI. For patients with MCI, exercise training probably improve cognitive measures and cognitive training possibly improve cognitive ability. It is recommended that clinicians should assess MCI with validated tools, evaluate patients with MCI for modifiable risk factors and functional impairment, assess and treat behavioral/neuropsychiatric symptoms. Clinicians should monitor cognitive status of patients with MCI over time. Cognitively impairing medications should be discontinued. Clinicians should recommend regular exercise and cognitive training for patients. The guideline does not recommend that clinicians provide cholinesterase inhibitors for MCI patients.