Due process requires courts to make decisions based on the evidence before them without regard to information outside of the record. Skepticism about the ability of jurors to ignore inadmissible information is widespread. Empirical research confirms that this skepticism is well founded. Many courts and commentators, however, assume that judges can accomplish what jurors cannot. This Article reports the results of experiments we have conducted to determine whether judges can ignore inadmissible information. We found that the judges who participated in our experiments struggled to perform this challenging mental task. The judges had difficulty disregarding demands disclosed during a settlement conference, conversation protected by the attorney-client privilege, prior sexual history of an alleged rape victim, prior criminal convictions of a plaintiff, and information the government had promised not to rely upon at sentencing. This information influenced judges' decisions even when they were reminded, or themselves had ruled, that the information was inadmissible. In contrast, the judges were able to ignore inadmissible information obtained in violation of a criminal defendant's right to counsel and the outcome of a search when determining whether probable cause existed. We conclude that judges are generally unable to avoid being influenced by relevant but inadmissible information of which they are aware. Nevertheless, judges displayed a surprising ability to do so in some situations.