The aim of this study was to evaluate whether VEP is sensitive to optic neuritis (ON) when compared with triple dose orbital MRI. Twenty-four relapsing-remitting MS (RRMS) patients were included in the study. Group I (n = 10) patients with acute ON, Group II (n = 8): patients presenting with a current relapse who had the history of ON in the previous relapses. Group III (n = 6): patients presenting with a current relapse but with no history of ON. Neuro-ophtalmological evaluation. VEP investigation and orbital MRI with triple dose (0.3 mmol/kg) gadolinium (Gd) were carried out for all. VEP was found to be 70% sensitive and 12.5% specific to the acute ON, whereas orbital MRI with triple dose Gd was 70% sensitive and 100% specific. In chronic ON, the sensitivity of orbital MRI is 0%, whereas the VEP is still 75% sensitive to chronic optic nerve involvement and can distinguish the pathology 100% specifically. In conclusion, orbital MRI with triple dose Gd is not more sensitive than VEP in determining the acute optic nerve pathologies but it is a 100% specific method. The results suggest that VEP is superior to the orbital MRI in determining the chronic optic nerve involvement.