Abstract: The need for a specific standard test for Rheumatoid Arthritis (RA) cannot be overemphasized. In many instances, either the clinical diagnosis or the disease classification according to America College of Rheumatology (ACR) criteria is used as the basis for defining whether the patient has RA or not. However, predicting the clinical outcome of RA in a patient is more important for therapeutic decision making than predicting whether an arthritis syndrome will ever satisfy a set of classification criteria. The aim of this study was to compare anti-Cyclic Citrullinated Peptide test with those of Rheumatoid Factor (RF) and its isotypes RF-IgA and RF-IgM for early and differential diagnosis of RA. In a cross-sectional study, the concentrations of RF and its isotypes RF-IgA and RF-IgM and anti-Cyclic Citrullinated Peptide were determined in 102 classified and unclassified RA patients and 50 citrullinated peptide antibodies, rheumatoid factor., Rheumatoid factor-immunoglobulin M and A (RF-IgM, RF-IgA) (51.75%). The high specificity of anti-CCP combined with the high sensitivity of RF-IgM infers that a combination of anti-CCP and RF-IgM is a good predictor for early diagnosis and course of RA.