
714 So.2d 1195 (1998)
David B. KNAFEL, Appellant,
v.
STATE of Florida, Appellee.
No. 98-02495.
District Court of Appeal of Florida, Second District.
August 5, 1998.
PER CURIAM.
David Knafel appeals the trial court's denial of his motion to mitigate his sentence filed pursuant to Florida Rule of Criminal Procedure 3.800(c). This order is not appealable, and this appeal would customarily be subject to dismissal. See Lee v. State, 662 So.2d 731 (Fla. 2d DCA 1995). The trial court's authority to deny a modification or mitigation of a sentence is entirely discretionary. In his notice of appeal, however, Knafel raises a legal issue for which review might lie; to-wit, whether a judge other than the one who imposed sentence should properly have ruled upon such a motion, as was the case in the trial court. This court may exercise its certiorari jurisdiction to review unsuccessful motions to mitigate if they question matters not wholly within the trial court's discretion. See Brown v. State, 707 So.2d 1191 (Fla. 2d DCA 1998). We note that Knafel's motion was filed six months after the sentence was imposed of which he complains, and, as no appeal was taken from that sentence, his motion was untimely filed in the trial court. See Fla. R.Crim. P. 3.800(c). Accordingly, we treat Knafel's attempt to appeal the denial of the motion as a petition for writ of certiorari, and, because no manifest injustice has been demonstrated, deny the petition.
BLUE, A.C.J., and GREEN and CASANUEVA, JJ., concur.
