OBJECTIVES: To present preliminary baseline data on the treatment of Attention-Deficit/Hyperactivity Disorder (ADHD) symptoms and on observed co-morbid problems in German patients enrolled in the ADORE study (Attention Deficit Hyperactivity Observational Research in Europe). METHODS: ADORE is an ongoing 24 month, pan-European, prospective, observational study to describe the relationship between treatment regimen prescribed and quality of life in ADHD. Only patients not formally diagnosed with ADHD previously were included. RESULTS: A total of 392 patients with a mean age of 8.7 (SD 2.1) years with inattentive/impulsive/hyperactive symptoms were enrolled, of which 300 (77%) were male. ADHD symptoms were first observed at a mean age of 5.0 (SD 2.5) years, while treatment was first sought at a mean age of 7.1 (SD 2.3) years. A total of 384 subjects (98%) were formally diagnosed with ADHD at baseline for the first time - the vast majority according to DSM IV or ICD 10 criteria. The mean baseline score on the ADHD Rating Scale-IV was 33.0 (SD 9.0). The mean Clinical Global Impression-Severity score was 4.4 (SD 0.9). The most commonly reported comorbid psychiatric symptoms were related to: oppositional defiant (N=271 (69%)) and conduct (N=240 (61%)) disorders, anxiety (N=108 (28%)) and learning disorders (N=243 (62%)). Investigators prescribed pharmacotherapy in 78 cases (20%), some form of psychotherapy in 66 cases (17%), and a combination of pharmacotherapy and psychotherapy in 84 cases (21%). Short-acting methylpenidate was prescribed for 159 (95%) out of 162 patients (41%) receiving pharmacotherapy. Psychoeducation/counselling was prescribed for 156 (40%) and cognitive behavior therapy for 44 (28%) of the patients/families. CONCLUSIONS: Baseline data showed: 1) an average gap of two years between first symptoms and seeking treatment; 2) frequent comorbid problems; and 3) prescription of some form of treatment in approximately two thirds of patients.