Studies on the influence of expert evidence and judicial instructions in child sexual abuse (CSA) cases have produced mixed outcomes. Using repeated measures, we tested the effectiveness of expert evidence and judicial directions in challenging common misconceptions about children's memory and responses to sexual abuse. A CSA Misconceptions Questionnaire was administered to 118 psychology undergraduates who later served as virtual jurors in a simulated criminal trial. Specialized CSA knowledge was provided by a psychologist or via judicial directions. Expert evidence had two levels: clinical versus scientific testimony. Timing of judicial instructions had two levels: directions presented before the child testified versus during the judge's summing up. In a fifth control condition, no specialized CSA information was included. After reading a trial transcript, mock-jurors assessed witness credibility, rendered verdicts and again completed the CSA Misconceptions Questionnaire. All four interventions significantly increased jurors' CSA knowledge. The more they knew, the more likely they were to convict. Perceived victim credibility fully mediated the effect of CSA knowledge on verdict: information presented via expert testimony or judicial directions enhanced perceptions of victim credibility, which in turn increased convictions. Conviction rates were significantly higher in response to expert testimony from a clinical psychologist and a judicial instruction provided in the trial summation. These results are promising for courts and policy-makers grappling with low conviction rates in CSA jury trials.