A total of 250 participants read a case summary and partial transcript including the expert testimony of a neuropsychologist who evaluated the plaintiff for a suspected mild traumatic brain injury (mTBI) in a personal injury trial. There were three diagnostic conditions (organic injury, psychogenic reaction, or malingering) to which participants were randomly assigned, along with two requested award amounts ($10,000 or $5 million). Both pre-and postdeliberation effects emerged for the diagnosis (largest awards for the organic mTBI condition) and for the award request (larger requests resulted in larger awards), with the effect size for award request being substantially larger than the clinical diagnosis. A significant interaction also emerged, whereby the effect of the clinical diagnosis was only present when the award request was large. Thus, factors that are potentially less relevant to pain and suffering (award request) may disproportionately impact mock juror decisions in personal injury trials relative to factors that should be more salient (the expert witness's diagnosis). However, the award request had no impact on mock juror perceptions of the injury's life impact, sympathy for the plaintiff, or perceived plaintiff credibility, but the diagnosis did influence these outcomes. Implications for civil litigation in mTBI trials are discussed.