The analysis focuses on what penal rationale, if any, is used; the impact of the guidelines on correctional resources; incentives for avoiding the guidelines; and prospects for improving the guidelines over time. The principal feature of the U.S. sentencing guidelines is a grid with an offense score as the vertical axis and a criminal-history score as the horizontal axis. Within the grid are cells that set forth the normally recommended range of sentences. The U.S. Sentencing Commission's grid calls for custodial sentences for most crimes; however, there is considerable flexibility to deviate from the grid ranges. This combination of severe grid sentences and loose departure rules portends problems. If the severe sentences recommended in the grid are followed, then there will be a heavy drain on correctional resources and prison overcrowding. If there are significant sentencing departures from the guidelines, then sentencing disparity is likely to result. To compound the problem, the U.S. Parole Commission's guidelines will no longer operate to restrain divergences among prison sentences. The Canadian sentencing guidelines avoid the severity of the U.S. guidelines and emphasize nonincarcerative sanctions for most offenses. Proposals for improving the U.S. sentencing guidelines are offered. 103 footnotes