The introduction of new immunomodulatory therapies such as, interferon-beta, glatiramer acetate (Copaxone, Teva Pharmaceutical Industries) and mitoxantrone (Ralenova, Wyeth Pharma; Novantrone, Immunex Corp.) has considerably improved the therapeutic options for patients with multiple sclerosis. These agents have been shown to reduce relapse rate, slow down progression of disability and prevent the accumulation of magnetic resonance imaging lesion load in clinically definite multiple sclerosis. Moreover, two formulations of interferon-beta delayed conversion into clinically definite multiple sclerosis in patients with clinically isolated syndromes suggestive of multiple sclerosis. Since axonal damage leading to irreversible neurological disability is already present early at the onset of the disease, immunomodulatory therapy should start as soon as possible. This article reviews the arguments for the early initiation of therapy and provides an overview of clinical studies dealing with the early treatment of multiple sclerosis.