Tehran University of Medical Sciences (TUMS) Academic Journal of Surgery 2423-3218 6 1 2023 12 10 1 6 Ehsan Sobhanian MD,General Surgeon,Department of Surgery, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran Zahra Moghimi Department of Gynecology, Yas Hospital, Tehran University of Medical Sciences, Tehran, Iran Aidin Yaghoobi Notash General Surgeon and Faculty Member, Tehran University of Medical Sciences,Tehran,Iran Hadi Ahmadi Amoli Sina Trauma and Surgery Research Center, Tehran, University of Medical Sciences, Tehran, Iran Ehsan Sadeghian MD,Board Certified General Surgeon,Department of Surgery,Shariati Hospital,Tehran University of Medical Sciences,Tehran,Iran Ali Sobhanian Department of pharma economy, Faculty of pharmacy, Tehran medical science, Islamic azad university, Tehran, Iran 2022 12 25 Introduction: Anastomosis leakage is a pivotal post colorectal surgery complication that jeopardizes patients’ survival and unspecific clinical presentations elongates the diagnosis process that could exacerbate the efficacy of interventions. This has raised the need for identifying a biomarker that potentiates early prediction of AL. Former studies have indicated the potential utility of WBC, C-reactive protein (CRP), and procalcitonin (PCT) serum levels as biomarkers for early AL detection. Therefore, this study was proceeded aiming to investigate the potential correlation of these markers with the manifestation of AL. Materials and Methods: patients referring to the hospitals of Tehran University of medical sciences from November 2018 to January 2020 were evaluated for inclusion in the study and after obtaining informed consents, 277 cases were enrolled in the study. WBC, CRP, and PCT serum level were measured preoperatively and up to five days post operation and statistical correlation analysis was conducted using SPSS software (version 24).  Results: Among 277 cases, 14 manifested AL. Accordingly, the highest sensitivity and specificity for AL was for CRP at second and third post-operative days. PCT however indicated higher utility on the fourth post-operative day with 57% sensitivity, 56% specificity (p-value = 0.001 for the second day and 0.002 on the third day), and the negative predictive value was 96%. These numbers altered to 36%, 64%, and 95% respectively on the fifth post-operative day that sustains within the acceptable range (p-value = 0.018). Conclusion: Both CRP and PCT devise the potential utility as a diagnostic biomarker considering the presence of AL and can remarkably accelerate the diagnosis period. To attain the highest sensitivity and specificity, CRP is to be used at the second and third post-operative days. The optimum utility for PCT however is on the fourth post-operative day. https://ajs.tums.ac.ir/index.php/ajs/article/view/229 https://ajs.tums.ac.ir/index.php/ajs/article/download/229/104