BACKGROUND: Anti-mutated citrullinated vimentin (MCV) antibodies have recently been recommended as a better arthritis diagnostic marker. OBJECTIVES: To investigate the association between anti-MCV antibodies and the clinical, functional, and radiographic characteristics of rheumatoid arthritis (RA) patients. METHODS: This case-control study was conducted on 40 RA patients and 40 healthy subjects. All patients were subjected to an assessment of disease using the 28-joint DAS (DAS28) and Clinical Disease Activity Index (CDAI), function by HAQ-DI, physical activity by International Physical Activity Questionnaire (IPAQ), fatigue by Functional Assessment of Chronic Illness Therapy (FACIT), serological tests as well as anti-MCV Abs measurement. A plain X-ray of both hands and wrists was done. RESULTS: The anti-MCV Abs level was significantly higher in RA patients than in healthy controls (P< 0.001). The anti-MCV Abs had a significant positive correlation with DAS, CDAI, HAQ, RF, Anti-CCP, and CRP (P= 0.006, 0.013, 0.005, < 0.001, < 0.001and 0.041 respectively) and a significant negative correlation with FACIT (p= 0.007). Positive anti-MCV RA patients had significantly higher erosions, JSN, and a total sharp score. CONCLUSIONS: Anti-MCV Abs may contribute to poor physical activity and more fatigue in RA patients beyond their established role in disease activity and erosion.