The federal presentence investigation report (PSR) is the document most heavily relied on by a judge in imposing sentence—particularly in those cases where a guilty plea has been entered and the court knows little about the defendant. It also is the document that the Federal Bureau of Prisons (BOP) relies on in making designations and placements and many other decisions throughout an inmate’s period of incarceration, including, but not limited to, whether to grant early release through halfway house and, if so, for how much time. In this article, published in the ABA’s Criminal Justice Magazine, Fall 2014, Alan Ellis discusses how PSRs are prepared and their content, and gives guidelines for defense attorneys who wish to object to the PSR prepared for their client.