The county court has appellate jurisdiction over JP and municipal court cases (for municipal court cases, this may involve a trial de novo if the lower court is not a "court of record"), exclusive jurisdiction over "Class A" and "Class B" misdemeanors (these offenses can involve jail time), and concurrent jurisdiction over civil cases where the amount in controversy is moderately sized. There is no requirement that the judge of the Constitutional County Court be an attorney.

Since the county judge is also responsible for presiding over the Commissioners Court (the main executive and legislative body of the county), in most counties the Texas Legislature has established county courts at law. In most counties with courts at law, the civil and criminal jurisdiction of the constitional county court has been transferred to the county courts at law. County court at law judges are required to be attorneys.

In another unique twist, the Constitution grants the Legislature the authority to determine which court handles probate matters. Thus, in ten of the 15 largest counties, the Legislature has established a Statutory Probate Court, which handle matters of probate, guardianship, and mental health commitments to a state mental hospital.