Zabrana reformatio in peius neizostavna je komponenta vladavine prava, koja počiva na postulatu pravednosti kažnjavanja u obliku jamstva okrivljeniku da žalba podnesena samo u njegovu korist neće rezultirati donošenjem presude na njegovu štetu, odnosno strožom osudom od one na koju je žalba izjavljena. Učinak zabrane dalekosežan je i premašuje okvire pravomoćnosti odluke budući da zabrana reformatio in peius nakon uspostave vrijedi i nakon pravomoćnosti odluke, u postupku u povodu izvanrednih pravnih lijekova izjavljenih u korist osuđenika, sve do konačnosti odluke. Iako iz teksta samog zakona proizlazi da se zabrana reformatio in peius aktivira podnošenjem pravnog lijeka samo u korist okrivljenika, razvidno je da zabrana nastupa u situaciji kada se državni odvjetnik uopće nije žalio na presudu ili se nije žalio u određenom smjeru (premda je uložio žalbu protiv presude). U pravnoj teoriji i sudskoj praksi nesuglasje izaziva opseg primjene zabrane reformatio in peius u žalbenom postupku. Naime, u pravnoj teoriji zastupljeno je stajalište da (samo) podnošenje žalbe na štetu okrivljenika anulira aktivaciju predmetne zabrane, stoga dvojbe pobuđuju situacije kada je pravni lijek, doduše, izjavljen na štetu okrivljenika, ali je odlukom suda odbačen kao nedopušten ili nepravodoban, odnosno odbijen kao neosnovan, ili situacije u kojima je državni odvjetnik podnio žalbu protiv presude, ali je presuda ukinuta po službenoj dužnosti ili u povodu žalbe okrivljenika zbog bitne povrede odredaba kaznenog postupka, čime je žalba državnog odvjetnika postala bespredmetna. Autorice u radu analiziraju normativno uređenje zabrane reformatio in peius u Republici Hrvatskoj, kao i sudsku praksu, napose županijskih sudova, Visokog kaznenog suda Republike Hrvatske i Vrhovnog suda Republike Hrvatske u cilju pronalaženja odgovora na dvojbene situacije koje se pojavljuju u praksi sudova.The prohibition of reformatio in peius is an indispensable component of the rule of law, which rests on the postulate of the fairness of punishment in the form of a guarantee to the defendant that an appeal filed only in the defendant’s favour will not result in a judgment to the defendant’s detriment, i.e., a harsher sentence than the one against which the appeal was filed. The effect of the prohibition is far reaching and exceeds the scope of the finality of the decision since the prohibition of reformatio in peius, once established, is valid even after the finality of the decision, in the procedure for extraordinary legal remedies declared in favour of the convicted person, until the final conclusion of the proceedings. Although it follows from the text of the law itself that the prohibition of reformatio in peius is activated by submitting a legal remedy only in favour of the defendant, it is clear that the prohibition occurs in a situation where the state attorney did not appeal the verdict at all or did not appeal in a specific direction (although he or she filed an appeal against the judgment). In legal theory and jurisprudence, the scope of application of the prohibition of reformatio in peius in the appellate procedure causes disagreement. In legal theory, there is a point of view that (only) filing an appeal to the defendant’s detriment cancels the activation of the prohibition in question. Therefore, doubts arise in situations where the legal remedy was, admittedly, declared to the detriment of the defendant but was rejected by the court’s decision as inadmissible or untimely, that is, rejected as unfounded, or in situations in which the state attorney filed an appeal against the verdict, but the verdict was revoked ex officio or on the occasion of the defendant’s appeal due to a significant violation of the provisions of the criminal procedure, which rendered the state attorney’s appeal moot. In the paper, the authors analyse the normative regulation of the prohibition of reformatio in peius in the Republic of Croatia, as well as the case law, especially of the county courts, the High Criminal Court of the Republic of Croatia, and the Supreme Court of the Republic of Croatia to find answers to doubtful situations that arise in the practice of the courts
