This review summarizes the current knowledge regarding the functions of PGC-1α in the brain and its role in neurological diseases, such as intracerebral hemorrhage (ICH), ischemic stroke, Alzheimer’s disease (AD), Parkinson’s disease (PD), Amyotrophic lateral sclerosis (ALS), and Polyglutamine (PolyQ) diseases. This evidence concerns the gene PPARGC1A and early-onset autosomal dominant Alzheimer disease.