This study evaluated the efficacy and safety of Lofexidine in treating children with tic disorders and attention deficit hyperactivity disorder (ADHD). Subjects from a specialty tic disorders clinic were randomly assigned to receive 8 weeks of treatment with lofexidine or placebo under double-blind conditions. Follow-up visits occurred every 2 weeks for safety monitoring and dose adjustment. Fourty-four medication-free subjects (41 boys and three girls; mean age of 10.4 years) with ADHD, combined type, and a tic disorder participated. After 8 weeks of treatment, lofexidine was associated with a mean improvement of 41% in the total score on the teacher-rated ADHD Rating Scale compared to 7% improvement for placebo. Eleven of 22 subjects who received lofexidine were blindly rated on the Clinical Global Scale-Improvement as either much improved or very much improved compared to none of 22 subjects who received placebo. The mean score on the parent-rated hyperactivity index improved by 29% in the lofexidine group and 18% in the placebo group, which was not a significant difference. On the Continuous Performance Test, commission errors decreased by 25% and omission errors by 20% in the lofexidine group, compared with increases of 33% in commission errors and of 36% in omission errors in the placebo group. Tic severity decreased by 27% in the lofexidine group, compared to 0% in the placebo group. One lofexidine subject with sedation withdrew at week 4. Lofexidine was associated with insignificant decreases in blood pressure and pulse. Lofexidine appears to be a safe and effective treatment for children with tic disorders and ADHD.