Background and Objectives: Botulinum neurotoxin A (BoNT-A) is the fi rst line treatment for cervical dystonia (CD). Three different preparations are available: abobotulinumtoxinA, onabotulinumtoxinA, and incobotulinumtoxinA. However, potencies between these preparations vary and the products are therefore not easily interchangeable. Methods: We retrospectively compared the treatment plans and outcome of 51 patients with CD who were treated either with abobotulinumtoxinA (n = 19), onabotulinumtoxinA (n = 20), or incobotulinumtoxinA (n = 12). Results: There were no differences between the three treatment groups in respect to time of fi rst improvement of symptoms (TIS), duration of symptom relieve (DSR), or maximum benefi t (MaxB). However, the total units used for treatment in the abobotulinumtoxineA group was signifi cantly higher than in both other groups, thus resulting in a conversion ratio of 4:1for abobotulinumtoxinA to onabotulinumtoxinA and a conversion ratio of 4.3:1 for abobotulinumtoxinA to incobotulinumtoxinA. Conclusion: In clinical practice, the conversion ratio between abototulinumtoxinA and onabotulinumtoxineA might be higher than previously indicated by prospective studies or in mouse assays. Consequently, lager studies are needed to determine the conversion ratio of the different preparations available as well as the optimization of doses and selection of preparation, therefore resulting in improved cost-effectiveness of different treatment options in clinical practice.