This is an original action in this court for an order prohibiting respondent from proceeding further in an action pending in the Bullitt Circuit Court. The petitioners are nonresidents and were served with summons at the court house in Jefferson County, Kentucky.

Petitioners filed a motion to quash the return of the summons. They alleged that, as nonresidents whose presence in this state was solely for the purpose of at*796tending court hearings in litigation in which they were parties, they were immune from service of process. The motion to quash was overruled. This action followed.

The writ of prohibition is an extraordinary remedy authorized by § 110 of the Kentucky Constitution. Its use by this court is discretionary and it is used only when the exigencies of a situation are so exceptional that no other remedy is adequate to prevent a miscarriage of justice. Brown v. Knuckles, Ky., 413 S.W.2d 899 (1967).

The circuit court has subject-matter jurisdiction of this action. No irregularity is shown to exist on the face of the summons. If the court has erred in refusing to quash the return on the summons, the petitioners have an adequate remedy by appeal.

The petition for writ of prohibition is denied.