Objective: The objective of this analysis was to evaluate the effect of botulinum toxin type A on quality of life in patients with cervical dystonia. Methods: The study consisted of a 10-week, nonrandomized, open-label period followed by a 10-week, randomized, double-blind, placebo-controlled, multicenter, parallel-group period. Patients were randomized to receive either botulinum toxin type A, at a dose determined by the physician based on the patient's established prestudy treatment regimen and the patient's presentation, or placebo. Patients completed the SF-36 Health Survey to evaluate the following quality of life attributes: physical functioning, role limitations due to physical health, role limitations due to emotional problems, energy/fatigue, emotional well-being, social functioning, pain, and general health. Results: A total of 170 patients were randomized to treatment. A significant difference was seen in the change from week 0 to week 6 for the physical functioning domain in which the botulinum toxin group had a mean change of 2.00 (improvement) and the placebo group had a mean change of -3.03 (worsening) (P=0.036). Botulinum toxin produced greater improvement than placebo for all other domains except social functioning; however, the differences between groups were not significantly different. Rates of adverse events were nearly equivalent between groups (59.1% BoNT-A vs. 58.5% placebo group). Conclusion: Prior literature indicates that the SF-36 is not a sensitive measure of the change in quality of life due to treatment in the cervical dystonia population. Despite this, the botulinum toxin type A treatment group showed significantly improved physical functioning. Furthermore, important trends were identified in other domains.