Peer Reviews of Expert Opinions in Ukrainian Courts: Evidence or Not?

In Ukrainian IP litigation, the court expert’s opinion often decides the case: trademark similarity or the use of industrial property is almost always established through special knowledge. Unsurprisingly, parties look for ways to shake such an opinion – and one of the most popular tools of recent years has been the peer review (recenziia) of the expert’s opinion. But is it evidence? A year ago the Supreme Court said yes. In January 2026 the answer became no.

Why the Question Arises

Where the facts in issue require special knowledge outside the law, the court expert’s opinion frequently becomes the pivotal piece of evidence – nowhere more so than in intellectual property disputes.

At the same time, no evidence has predetermined force for the court, and proceedings are adversarial. So the party against whom the expert opinion cuts will try to dismantle it. Some commission an alternative examination from another expert; some move for a court-appointed examination. Others take a third route: they file a peer review of the expert’s opinion – a document in which another specialist critiques the methods, completeness and logic of the examination.

The difficulty is that Ukrainian procedural law regulates neither the status of such a review nor how courts should treat it. Hence three practical questions: how should a court assess a review that is not itself an expert opinion but argues the examination was flawed? Can it have independent evidentiary value? And is the court obliged to address its arguments at all?

The 2021-2025 Position: a Review Is Evidence, and Courts Must Assess It

For several years the Commercial Cassation Court within the Supreme Court answered these questions consistently. In its rulings of 14 January 2021 in case No. 922/2216/18 and 8 April 2025 in case No. 910/14228/21, the Court held that an appellate court’s failure to assess a review submitted by a party breaches the adversarial principle and Article 86 of the Commercial Procedure Code, which requires comprehensive, complete and objective examination of the evidence.

Moreover, refusing to consider a review merely because a party commissioned it, and inferring the reviewer’s bias on that basis alone, was itself held to violate the adversarial principle. The fact that a party paid for the review did not entitle courts to ignore it.

In its ruling of 29 May 2025 in case No. 910/2059/20, the Supreme Court added an important clarification, relying on the Procedure for Reviewing Court Experts’ Opinions approved by Ministry of Justice Order No. 335/5 of 3 February 2020: a review is not a repeat or additional examination and does not assess evidence – the reviewer evaluates the methods, completeness and logic of the expert’s work. Accordingly, the formal requirements applicable to expert opinions do not extend to reviews.

✅ The settled 2021–2025 position (Commercial Cassation Court) in brief
1. A peer review of an expert opinion is evidence, and the court must assess it.
2. Assessment takes into account the Review Procedure approved by MoJ Order No. 335/5 of 03.02.2020.
3. A review is not a repeat or additional examination – expert-opinion requirements do not apply to it.

January 2026: a 180-Degree Turn

In early 2026 the Supreme Court expressed the diametrically opposite view. In its ruling of 16 January 2026 in case No. 753/22492/19, the Civil Cassation Court agreed with the appellate court that a peer review of an expert opinion is not evidence within the meaning of the Civil Procedure Code and cannot rebut a court-ordered examination, because the institution of peer review is of a purely intra-professional character and is not designed to influence the assessment of evidence in judicial proceedings.

Where a review was previously treated as evidence the court was obliged to assess, it has now effectively been excluded from the body of evidence – at least in civil proceedings.

✅ 2021–2025 • Commercial Cassation
“A review is evidence”
Cases No. 922/2216/18, No. 910/14228/21, No. 910/2059/20.
Ignoring a review = breach of the adversarial principle and Art. 86 CommPC.
That a party commissioned the review is no ground to disregard it.

⚠️ 2026 • Civil Cassation
“A review is not evidence”
Case No. 753/22492/19 (ruling of 16.01.2026).
Peer review is an intra-professional institution.
It is not designed to influence the assessment of evidence and cannot rebut the examination.

Where That Leaves Us: Legal Uncertainty

The procedural status of the peer review is, for now, an open question. The divergence between the Commercial and Civil Cassation Courts within the Supreme Court shows that no final, unified position has yet formed.

A jurisdictional nuance matters here: the “review is evidence” line developed mainly in commercial procedure, while the “review is not evidence” line arose in civil procedure. That makes the split no less sensitive: IP disputes are heard in both jurisdictions, and the same review may today meet a different procedural fate depending on which court hears the case. A definitive answer could come from the Grand Chamber of the Supreme Court.

Practical Guidance While the Position Remains Unsettled

• Do not rely on a peer review as your sole tool for attacking an expert opinion – especially in civil proceedings. After the ruling of 16.01.2026, the risk that the court will decline to assess it has grown considerably.
• Use the review tactically: the flaws it identifies can ground motions to summon the expert for questioning or to order a repeat or additional examination.
• In commercial proceedings the review still carries practice-backed weight – and if the court left it unassessed, that is an argument on appeal or cassation, citing cases No. 922/2216/18 and No. 910/14228/21.
• If you rely on the expert opinion, do not ignore the opponent’s review: prepare substantive objections to each of its arguments, even while maintaining that it is not evidence.
• Watch the case law: the issue is ripe for unification, and a new Supreme Court position may change the landscape at any moment.

This material is of a general informational nature, reflects the law and practice as at the date of publication, and does not constitute legal advice. For an assessment of your specific situation, we recommend consulting a qualified professional.