Natalizumab is a potent immunosuppressive monoclonal antibody used for the treatment of multiple sclerosis (MS). While definite guidelines for the safety of natalizumab prescriptions are available in all countries, there are no specific recommendations on how to withdraw the drug if the need arises. There are reports describing MS complications after natalizumab infusions were stopped. Most neurologists seem to stop natalizumab treatment according to their idea on how to best carry out the withdrawal. The present study shows the very different manners in which expert neurologists from 14 MS units in Brazil stopped natalizumab in their patients. The authors concluded that pharmacovigilance on natalizumab must persist after the drug is withdrawn in order to have enough data for adequate recommendations.