In the past 20 years the treatment scenario of multiple sclerosis has radically changed. The increasing availability of effective disease-modifying therapies has shifted the aim of therapeutic interventions from a reduction in relapses and disability accrual, to the absence of any sign of clinical or MRI activity. The choice for therapy is increasingly complex and should be driven by an appropriate knowledge of the mechanisms of action of the different drugs and of their risk-benefit profile. Because the relapsing phase of the disease is characterised by inflammation, treatment should be started as early as possible and aim to re-establish the normal complex interactions in the immune system. Before starting a treatment, neurologists should carefully consider the state of the disease, its prognostic factors and comorbidities, the patient's response to previous treatments, and whether the patient is likely to accept treatment-related risks in order to maximise benefits and minimise risks. Early detection of suboptimum responders, thanks to accurate clinical monitoring, will allow clinicians to redesign treatment strategies where necessary.