OBJECTIVE: Assess utilization of Dysport and BOTOX for cervical dystonia and blepharospasm and compute the cost consequences of toxin selection. METHODS: Six European study sites abstracted drug utilization data from the records of their patients who had received Dysport then BOTOX or BOTOX then Dysport in a drug crossover that occurred in clinical practice. To reduce potential selection bias and confounding variables, patient records were screened for study inclusion/exclusion criteria during scheduled clinic visits. Patients were screen-qualified if they were >18 years of age, medically stable, responsive to persistent toxin therapy for >1 year before and after drug crossover, did not receive other medications that affect neuromuscular transmission, and were not involved in another drug study. Mean per-patient, per-visit and total toxin dose, dosing ratio (Dysport: BOTOX), and frequencies of adverse drug reactions (ADRs) were computed along with break-even drug cost equivalence in 5 of 6 participating sites. RESULTS: One hundred fourteen screen-qualified patients (70 cervical dystonia, 44 blepharospasm) were assessed, providing 1,399 injections for evaluation. Ratios of mean dose (units) Dysport: BOTOX ranged from 2:1 to 11:1, with 88% of patients greater than 3:1, regardless of study site or direction of drug cross-over. ADRs were more frequently reported during Dysport treatment (11%) than during BOTOX treatment (4.25%). Drug unit cost equivalence (Dysport to BOTOX) based on local pricing were 2.0:1 for the Czech Republic, 3.91:1 in the UK (Hull and Essex), 4.16:1 in Slovenia, and 5.24:1 in Poland. When observed mean dose ratios were compared to cost equivalent ratios, the proportion of patients that would contribute to cost savings if BOTOX were exclusively utilized is 63 %. CONCLUSION: BOTOX utilization likely leads to cost savings, based on utilization and current pricing compared to Dysport. When other important considerations such as ADRs are considered, overall savings may be even greater.