Laquinimod (ABR-215062) is an oral immunomodulatory agent developed for the treatment of relapsing multiple sclerosis (MS). Laquinimod is a derivative of the drug roquinimex, but lacks the unacceptable side effect profile of this drug which was documented in previous MS trials. Preclinical studies in experimental models of MS, both of autoimmune neuroinflammation and of toxin induced demyelination show a multitude of immunomodulatory and anti-inflammatory effects, including some that are effective directly in the central nervous system. Phase I study results confirmed the safety and tolerability of laquinimod, and phase II and III studies provide a picture of a consistent albeit moderate effect on relapse rate and new lesion development on magnetic resonance imaging combined with a stronger effect on sustained progression and brain atrophy. These findings make laquinimod a potentially useful future treatment of MS.