We report the results of the cross-cultural adaptation and validation into the German language of the parent's version of two health related quality of life instruments. The Childhood Health Assessment Questionnaire (CHAQ) is a disease specific health instrument that measures functional ability in daily living activities in children with juvenile idiopathic arthritis (JIA). The Child Health Questionnaire (CHQ) is a generic health instrument designed to capture the physical and psychosocial well-being of children independently from the underlying disease. The German CHAQ was fully validated with 3 forward and 3 backward translations, while the CHQ has already been published and therefore it was revalidated. A total of 197 subjects were enrolled: 142 patients with JIA (5% systemic onset, 13% polyarticular onset, 8% extended oligoarticular subtype, and 74% persistent oligoarticular subtype) and 55 healthy children. The CHAQ clinically discriminated between healthy subjects and JIA patients, with the polyarticular and extended oligoarticular subtypes having a higher degree of disability, pain, and a lower overall well-being when compared to their healthy peers. Also the CHQ clinically discriminated between healthy subjects and JIA patients, with the polyarticular onset and extended oligoarticular subtypes having a lower physical and psychosocial well-being when compared to their healthy peers. In conclusion the German versions of the CHAQ-CHQ are reliable, and valid tools for the functional, physical and psychosocial assessment of children with JIA.