If a defendant in a criminal prosecution for DUI/DWI is found guilty, the defendant can appeal the conviction (finding of guilt) or the sentence (punishment such as jail or prison, restitution, community service, probation, etc.). An appeal is not another trial—it is an opportunity to raise specific errors that might have occurred at trial. For example, a convicted defendant might claim on appeal that the judge made an incorrect ruling on an important question such as whether to exclude or suppress certain evidence, or whether to impose a certain sentence or punishment. Appeals are complex processes and generally require the expertise of a licensed lawyer.

On appeal a conviction may be reversed, a sentence may be altered, or the case may be sent back to the trial court for a new trial or a new sentence. There are generally two potential levels of appellate review following a defendant’s conviction in a state court or federal trial court—an intermediate court (often called the court of appeals) and the highest court, or court of last resort (often the supreme court). Although a defendant usually has an automatic right to appeal a final conviction to the intermediate court of appeals, in many jurisdictions the highest court has discretion on whether to accept an appeal to review a case—known as discretionary review.

In Washington State, a defendant convicted of DUI/DWI has the right to appeal the conviction or the sentence. The appeal process is not a retrial but a legal proceeding where the defendant can challenge specific errors that may have occurred during the trial, such as improper evidence rulings or sentencing decisions. Appeals in Washington are typically heard first by the Washington Court of Appeals, which serves as the intermediate appellate court. If a party is dissatisfied with the decision of the Court of Appeals, they can petition the Washington Supreme Court, which is the state's highest court and court of last resort. The Supreme Court, however, has discretionary review, meaning it may choose whether or not to hear the appeal. It's important to note that appeals are complex and generally require the representation of an attorney with expertise in appellate law.