The diagnosis of Acute Appendicitis is mostly clinical through different scores; comparative assessment of Raja Isteri Pengiran Anak Saleha Appendicitis (RIPASA) score against modified ALVARADO score for the diagnosis of Acute Appendicitis would reveal the better score for clinical use.Evaluation of RIPASA score against modified ALVARADO score as a diagnostic score for Acute Appendicitis.A prospective study was conducted on all cases of suspected Appendicitis at a tertiary center from January 2021 to June 2022. Each patient was scored by both RIPASA and modified ALVARADO scores and Histopathological report for Appendicitis was taken as the gold standard. Both the scores were evaluated for their diagnostic ability.80 patients with suspected Acute Appendicitis with a mean age of 21.36years and with female predominance were scored by both RIPASA and modified ALVARADO scores. Sensitivity, specificity, Positive and Negative predictive values, Positive and Negative likelihood ratio, and area under ROC curve for RIPASA score (at 7.5 cutoff) were 94.74, 82.61, 93.10, 86.36, 5.45, 0.06 and 0.93; corresponding values for modified ALVARADO score (at 7.0 cutoff) were 59.65, 82.61, 89.47, 45.24, 3.43, 0.49 and 0.89 respectively. Both the scores had positive correlation when diagnosing an Acute appendicitis patient.RIPASA Score (at 7.5 cut-off) is a better diagnostic tool than modified ALVARADO Score (at 7 cut-off) due to better sensitivity, Positive and Negative predictive values, and higher area under the fitted ROC curve.