A court shall not find unconstitutional a statute, ordinance, regulation or other law, unless:
Rule 18.Findings of Unconstitutionality
Article I. General Rules · Last amended 2006 · Last verified July 20, 2026
In one sentenceRule 18 requires a trial court to document its reasoning in detail before it can declare a statute, ordinance, or regulation unconstitutional.
Full Text of Ill. S. Ct. R. 18
(a) the court makes the finding in a written order or opinion, or in an oral statement on the record that is transcribed;
(b) such order or opinion clearly identifies what portion(s) of the statute, ordinance, regulation or other law is being held unconstitutional;
(c) such order or opinion clearly sets forth the specific ground(s) for the finding of unconstitutionality, including:
(1) the constitutional provision(s) upon which the finding of unconstitutionality is based;
(2) whether the statute, ordinance, regulation or other law is being found unconstitutional on its face, as applied to the case sub judice, or both;
(3) that the statute, ordinance, regulation or other law being held unconstitutional cannot reasonably be construed in a manner that would preserve its validity;
(4) that the finding of unconstitutionality is necessary to the decision or judgment rendered, and that such decision or judgment cannot rest upon an alternative ground; and
(5) that the notice required by Rule 19 has been served, and that those served with such
notice have been given adequate time and opportunity under the circumstances to defend the statute, ordinance, regulation or other law challenged.
Plain-English Summary
Rule 18 sets a demanding checklist for any court that wants to strike down a law as unconstitutional. The finding has to appear in a written order or opinion, or in a transcribed oral statement, and it has to clearly identify which part of the statute, ordinance, or regulation is unconstitutional.
The order also has to spell out the specific constitutional provision at issue, whether the law fails on its face or only as applied to that case, and why the law cannot be read in a way that saves its validity. It must explain why the unconstitutionality finding is necessary to the decision, meaning the court could not have reached the same result on some other ground. Finally, it has to confirm that the notice required by Rule 19 was served and that the government had a real chance to defend the law.
Frequently Asked Questions
Can a judge declare a law unconstitutional from the bench without writing anything down?
Not under Rule 18. The finding must appear in a written order or opinion, or in an oral statement that is transcribed.
Does Rule 18 require the court to explain which part of the law is unconstitutional?
Yes. The order or opinion must clearly identify the specific portion being held unconstitutional.
Why does Rule 18 require notice under Rule 19 before a constitutional ruling?
Because the government entity defending the law needs a real opportunity to be heard before a court strikes it down, and Rule 18(c)(5) makes that notice a precondition to the finding.
Can a court find a law unconstitutional if the case could be decided on other grounds?
No. Rule 18 requires the finding to be necessary to the judgment, meaning the decision could not rest on an alternative ground.
Does Rule 18 distinguish between facial and as-applied challenges?
Yes. The order must state whether the law is being found unconstitutional on its face, as applied to the case, or both.
Committee Comments and Commentary
(July 27, 2006)
This rule is intended to implement the principles encapsulated in People v. Cornelius, 213 Ill. 2d 178 (2004), and In re Parentage of John M., 212 Ill. 2d 253 (2004), concerning the duties incumbent upon the circuit court when declaring state statutes to be unconstitutional.
Amendment History
Adopted July 27, 2006, effective September 1, 2006.
Source & verification. Rule text, official Committee Comments, and
amendment history are reproduced verbatim from the Illinois Supreme Court Rules,
promulgated by the Supreme Court of Illinois. Last verified July 20, 2026.
· Official source
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