Introduction: Acute appendicitis is a common surgical emergency in childhood and adulthood. However, perforated appendicitis is a condition that requires early diagnosis and treatment due to the increased risk of complications. In our study, we aimed to evaluate the clinical values of various biochemical, hematological, and inflammatory parameters in order to distinguish acute appendicitis from perforated appendicitis. Materials and methods: A total of 87 participants aged 18-65 y were enrolled in this prospective study. 29 patients with acute appendicitis, 29 patients with perforated appendicitis, and 29 healthy controls were included. Serum urea, creatinine, lactate dehydrogenase, and C-reactive protein concentrations were measured using an automated analyser, and whole blood parameters were measured using a haematological analyser. Total antioxidant status, total oxidant status, total thiol (TT), and native thiol (NT) levels were measured photometrically. Oxidative stress index and disulfide (DIS) level were calculated mathematically. Interleukin (IL)-1 beta, IL-6, tumor necrosis factor-a, and ischemiamodified albumin (IMA) levels were measured photometrically using commercially purchased kits. Results: The elevated levels of urea, lactate dehydrogenase, C-reactive protein, white blood cell, and platelet count in the acute and perforated appendicitis groups compared to stress index, DIS, DIS/TT, DIS/NT, and IMA) were higher, while antioxidant markers (total antioxidant status, TT, NT, and NT/TT) were lower in the appendicitis groups (P < 0.001). Additionally, inflammatory markers IL-1(3, IL-6, and tumor necrosis factor-a were elevated, particularly in the perforated appendicitis group (P < 0.05). Conclusions: IMA is a promising biomarker for distinguishing perforated appendicitis from acute appendicitis. Its role, in conjunction with other oxidative stress and inflammatory markers, may enhance diagnostic precision and aid clinicians in timely intervention, potentially reducing complications associated with delayed or missed diagnoses. Further studies are warranted to validate these findings. (C) 2025 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.