The past 40 years have been a time of great change in life sentencing, during which the use of life sentences has dramatically grown and the quality of life sentences has markedly hardened. The rise of life without parole in the United States is a particularly recognizable development, but life sentencing has increased worldwide, and the use of other forms of punishment that hold people in prison until death has also intensified. This article focuses on these transformations by examining several important areas in which thinking and scholarship on life sentencing have been altered and spurred by recent developments. The review concludes by pointing to gaps in the field of research and highlighting issues on which social scientific research on life sentencing has more to contribute going forward.