OBJECTIVES:  To determine 12-months administrative prevalence rate of tic disorders (TD) and Tourette syndrome (TS), as well as their coexistence with ADHD in a large German community sample, against the background of the clinical importance of this association.  METHODS:  Data for patients with a diagnosis of any tic disorder (F95, ICD-10), Tourette disorder (F95.2), or ADHD (F90.0 and/or F90.1) were extracted from the Nordbaden claims database, covering the complete subpopulation insured by Statutory Health Insurance (2.238 million lives in 2003; for comparison:  total German population insured by SHI in 2003, 70.2 million) in Nordbaden in South-Western Germany (representing 82% of the total regional population).  RESULTS:  A total of 3,618 patients with a diagnosis of any TD (hereof, 215 with TS) and 11,875 patients with ADHD were identified, corresponding to overall administrative prevalence rates (across all age groups) of 0.16% (TD), 0.01% (TS), and 0.53% (ADHD).  Males were generally more often afflicted with any of the disorders analyzed than females (TD, 0.19% versus 0.13% for females; TS, 0.02% versus 0.01%; ADHD, 0.83% versus 0.27%).  TD and TS were most prevalent among children 7-12 years (0.79% and 0.04%, respectively), and were significantly associated with presence of ADHD.  ADHD was reported in 11.2% of children age ≤12 years with TD (boys, 15.4%; girls, 4.5%), compared to 3.1% (boys, 4.4%; girls, 1.7%) in the community covered.  Among adolescents (age 13-18 years), a diagnosis of ADHD was tenfold more likely in patients with TD (15.1%; boys, 18.5%; girls, 7.7%) compared with the community group (1.5%; boys, 2.3%; girls, 0.7%).  CONCLUSIONS:  These data extend the epidemiological database by providing for the first time information from Germany on the administrative prevalence of TD, TS, and ADHD, as well as their coexistence, hereby highlighting the relevance of taking comorbidity into account when designing health care utilization and burden of disease studies: