Migraine is a common primary headache disease, which reduces quality of life. About 8% of migraineurs suffer from chronic migraine (CM), which is the most severe and troublesome type. It has been proven that onabotulinumtoxinA (ONA-BoNT/A) significantly improves CM, presumably inhibiting the release of calcitonin gene-related peptide (CGRP) and other neurotransmitters from c-fibres endings, and thus decreasing activation of nociceptive pathways and transmission of pain. The aim of this position paper was to assess the place of ONA-BoNT/A for the prophylaxis of CM in adults. The authors have compared the efficacy, safety and tolerance of the toxin to those of classical oral preventive therapies as well as to recently introduced anti-CGRP-pathway monoclonal antibodies. The results of randomised controlled studies of ONA-BoNT/A have been compared to open label (real world practice) trials.