Restak is a graduate of Gettysburg College and Georgetown University School of Medicine. He performed his postgraduate training in New York City at St. Vincent's Hospital (Manhattan) where he completed his internship. His first psychiatric residency was also in New York City at Mount Sinai Hospital. This was followed by two residencies in Washington,D.C.. A psychiatric residency at Georgetown University Hospital, and a residency in neurology at George Washington University Hospital.
Restak maintains a private medical practice in neurology and neuropsychiatry in Washington, D.C. where he is also a Clinical Professor of Neurology at George Washington Hospital University School of Medicine and Health.
He has to date written 18 books on various aspects of the human brain, two were on The New York Times Best Sellers List. His first bestseller, The Brain (1984), was also the first companion book he wrote for a PBS series. The Mind (1988), was his second bestseller.He has written articles for various national newspapers as well as appearing on radio and television programs.
He has appeared as an expert witness for the defense in the high profile trial of Mir Aimal Kasi. The Pakistani national charged with the 1993 shootings at CIA headquarters in Langley, Virginia. During the trial Restak testified that Kasi was missing tissue from his frontal lobes. A congenital defect that affected his ability to judge the consequences of his actions.