Multiple system atrophy (MSA) is an adult-onset sporadic progressive neurodegenerative disorder of unknown etiology. It is clinically characterized by the variable combination of autonomic failure, parkinsonism, cerebellar ataxia, and pyramidal signs. The present review summarizes up-to-date knowledge on the clinical diagnosis and molecular pathology of MSA. We also review the role of additional investigations that may support a clinical diagnosis of MSA. Finally, we briefly discuss the management of MSA, focusing on possible future therapeutic strategies.