Introduction: IgA nephropathy (IgAN) is the most common type of primary glomerulonephritis, and is the most common type of glomerulopathy which leading to end-stage renal disease (ESRD). Prompt diagnosis of high-risk patients is important to initiate specific treatment early and prevent progression to ESRD. Oxford pathological classification, known as MEST-C score, attempts to predict prognosis based on pathological factors. Objectives: In this study, we evaluated the value of pathological and clinical variables in estimating the prognosis of IgAN in Iranian patients. Patients and Methods: In this retrospective cohort study, 165 specimens were reviewed by a nephropathologist, who reported the MEST-C score after the definitive diagnosis of IgAN. Patient records were reviewed to gather clinical data, including serum creatinine, 24-hour urine protein levels, diagnosis of hypertension and/or diabetes, and any treatment received. The pre-specified endpoints were determined as progression to ESRD, a reduction in estimated glomerular filtration rate (eGFR) to less than 50% of its baseline, performance of renal transplant, or death. The variables were compared in patients who had reached the pre-specified endpoints and those who had not, to estimate their prognostic value. Results: Findings showed that the urinary protein level and T-score on biopsy were significant prognostic factors. Other pathological factors such as C, S, and M scores lost their significance on multivariate analysis. Further research is needed to validate the efficacy of the MEST-C score in different racial populations. Conclusion: In our study, urinary protein level at diagnosis and T-score on biopsy were validated as prognostic factors, while M, E, S and C scores were not deemed significant. Further research is necessary to validate the MEST-C scoring system in different populations before its use in routine clinical practice.