Multiple sclerosis (MS) is a chronic disease of the central nervous system with not yet completely understood pathogenesis. The so called "chronic cerebrospinal venous insufficiency (CCSVI) theory" has recently emerged, supporting the concept of a cerebrospinal venous drainage impairment as the cause of MS. Since the first publication on this topic with a claimed 100% specificity and sensitivity of the condition for MS diagnosis, CCSVI theory has generated a scientific and mass media debate with a great hope for the miracle of a new possible endovascular treatment of MS ("liberation procedure"). We critically summarize the available evidence on CCSVI discussing inconsistent and incomplete replication of the original results by different groups, methodological limitations and potential therapeutic implications. We conclude that the available data are insufficient to establish conclusively a clear relationship between MS and CCSVI and do not support the role of CCSVI as the primary cause of MS. Until credible scientific evidence replicates the original results, any proposed invasive treatments of CCSVI should be discouraged.