Aim:The aim of the study was to determine the usefulness of known biomarkers as pre-operative predictors of complicated acute appendicitis (CAA) and perforated appendicitis (PA). Materials and methods: This was an observational, analytic, cross-sectional, and prospective study at Hospital Teodoro Maldonado Carbo (August 2016-December 2017. Evaluated biomarkers: white blood cells count, neutrophil percentage (N%), neutrophil-to-lymphocyte ratio, glucose, total bilirubin, C-reactive protein, and procalcitonin (PCT). The statistical analysis was performed by means of the area under the receiver operating characteristics (AUROC) curve estimation. Biomarkers' cutoff point was identified using Youden's index. Sensitivity, specificity, positive, and negative predictive value (NPV) (positive predictive value [PPV] and NPV) were estimated. Results: One hundred and twenty-eight cases were included (median age 30 years, 44% female), 70 cases (54%) corresponded to CAA (PA 38/70).