That vaccines do not cause autism is now a widely accepted proposition, though a few dissenters remain. An 8-year court process in the US federal vaccine injury compensation court ended in 2010 with rulings that autism was not an adverse reaction to vaccination. There were two sets of trials: one against the measles-mumps-rubella (MMR) vaccine and one against the mercury-based preservative thimerosal. The MMR story is more widely known because of publicity surrounding the main proponent of an MMR-autism link, British doctor Andrew Wakefield, but the story of thimerosal in court is largely untold. This study examines the credibility battles and boundary work in the two cases, illuminating the sustaining world of alternative science that supported the parents, lawyers, researchers, and expert witnesses against vaccines. After the loss in court, the families and their advocates transformed their scientific arguments into an indictment of procedural injustice in the vaccine court. I argue that the very efforts designed to produce legitimacy in this type of lopsided dispute will be counter-mobilized as evidence of injustice, helping us understand why settling a scientific controversy in court does not necessarily mean changing anyone's mind.