Prejudicial pretrial publicity (PTP) constitutes a serious source of juror bias. The current study examined differences in predecisional distortion for mock jurors exposed to negative PTP (N-PTP) versus nonexposed control participants. According to work by K. A. Carlson and J. E. Russo (2001), predecisional distortion occurs when jurors bias new evidence in favor of their current leading party (prosecution or defense) rather than evaluating this information for its actual probative properties. Jury-eligible university students (N=116) acted as jurors in a mock trial. Elevated rates of guilty verdicts were observed in the N-PTP condition. Predecisional distortion scores were significantly higher in the N-PTP condition and reflected a proprosecution bias. The effect of prejudicial PTP on verdict outcomes was mediated by predecisional distortion in the evaluation of testimony. Results are discussed in relation to motivated decision making and confirmation biases.