A law firm/attorney can work on a case for an injured client on average of three to five years. Depending on the complexity of the case, it can take a longer or shorter time. If a case actually goes to trial, it can take a couple of weeks to months for the trial itself. Cases can be settled during the trial process as well. If not, then a jury will come to a verdict, based upon the evidence presented, either for the patient or the defense.