The geographical area served by each court is established by the legislature, but each county must be served by at least one district court. In sparsely populated areas of the State, several counties may be served by a single district court, while an urban county may be served by many district courts.

Smith County currently has four (4) District Courts. The 321st District Court is designated to hear only family law cases, while the other three district courts hear only civil and criminal matters.

While most district courts try both criminal and civil cases, in the more densely populated counties the courts may specialize in civil, criminal, juvenile, or family law matters. The Texas Judicial System, Office of Court Administration (March 2005).