Inclusion Criteria:

1. Male or female patients aged 6-17 years at the time of enrollment into study 248.641 or 248.644 and who have completed study 248.641 or 248.644.
2. Written informed consent provided by the patient's parent (or legal guardian) and assent provided by the patient consistent with ICH GCP and local Institutional Review Board (IRB) requirements for children obtained prior to any study procedures being performed.
3. Ability and willingness to comply with study treatment regimen and to complete study assessments.
4. Females of childbearing potential having a negative serum beta-HCG pregnancy test at Visit 1.
5. Females of childbearing potential must be using a medically accepted contraceptive method throughout the study. Acceptable methods of birth control are limited to: Intra-Uterine Device (IUD), oral, implantable, injectable contraceptives or estrogen patch, double barrier method (spermicide + diaphragm), or abstinence at the discretion of the investigator

Exclusion Criteria:

1. Breastfeeding females.
2. Development of any clinical condition in the preceding trial that in the investigator's opinion could be worsened by treatment with pramipexole.
3. Clinically significant renal disease or serum creatinine out of this range: 0.3 1.0 mg/dL for patients aged 3-12 years and 0.5-1.4 mg/dL for patients aged 13+ years.

4. Any of the following lab results at screening:

   Hemoglobin (Hgb) below lower limit of normal (LLN) which is determined to be clinically significant Basal thyroid stimulating hormone (TSH), triiodothyronine (T3) or thyroxine (T4) clinically significant (at the investigator's discretion) out of normal range at screening (if not caused by substitution therapy according the investigator's opinion) Patients with any clinically significant abnormalities in laboratory parameters at screening at the investigator's discretion.

5. Other clinically significant metabolic-endocrine, hematological, gastrointestinal disease, or pulmonary disease (such as severe asthma) in the opinion of the investigator that would preclude the patient from participating in this study.
6. History or presence of schizophrenia or any psychotic disorder. History or presence of any psychiatric disorder requiring medical therapy with the exception for patients with a diagnosis of TS, ADHD or OCD who are not on therapy other than pramipexole.
7. History or presence of clinical signs of epilepsy or seizures other than fever-related seizures in early childhood.
8. History or presence of clinical signs of any malignant neoplasm including suspicious undiagnosed skin lesion (which may be melanoma), melanoma, or a history of melanoma.
9. History of any other medical treatment for TS besides the study medication within 28 days prior to the baseline visit (14 days prior to baseline for guanfacine, 14 days prior to baseline for dopamine agonists, 14 days prior to baseline for L-Dopa, 35 days prior to baseline for fluoxetine).
10. Patients receiving psychotherapy are excluded unless they started the treatment at least 3 months prior to starting the trial and no changes in treatment are planned for the duration of the study.
11. Allergic response to pramipexole or the inactive ingredients in its tablet formulation.
12. Non-compliance with study medication (defined as less than 80% or more than 120%) during the preceding Study 248.641 or 248.644.
13. Concurrent participation in another clinical trial using any investigational drug since completion of the preceding Study 248.641 or 248.644.
14. Any other conditions, that in the opinion of the investigator, would interfere with the evaluation of the results or constitute a health hazard for the patient.