Objective: Acromegaly is a chronic disease with an important impact on quality of life. An acromegaly disease-generated quality of life questionnaire (AcroQoL) has recently been developed. We aimed to confirm reliability, construct validity and disease-specificity of the AcroQoL questionnaire. Second, we investigated the effect of remission status on health-related quality of life (HRQoL) in patients with acromegaly. Design and patients: Using a prospective, cross-sectional design, 33 patients with treated acromegaly and 22 patients with treated hormone-inactive pituitary adenoma under stable replacement therapy completed the German version of the AcroQoL questionnaire. Measurements and results: Cronbach's alpha analysis showed high reliability of the total score and the different scales and subscales in patients with acromegaly (alpha ranging from 0.83 to 0.93, item-total correlation 0.41-0.84). Patients with hormone-inactive pituitary adenoma showed lower reliability (alpha ranging from 0.17 to 0.75). Exploratory factor analysis in patients with acromegaly suggested a two-factorial solution with item distribution largely matching the scaling of the original Spanish questionnaire. Multiple regression analysis revealed significantly lower results of the total score and the different scales and subscales (indicating worse HRQoL) in patients with persistent acromegalic activity compared to patients with acromegaly in remission or discordant remission status. Consistently, IGF-I was an independent negative predictor of the different scores of the questionnaire. Conclusions: The AcroQoL questionnaire represents a reliable, construct valid and disease-specific tool for assessing health-related quality of life in patients with acromegaly. Patients with biochemically uncontrolled acromegaly showed significantly lower HRQoL than patients with acromegaly in remission or discordant remission status. © 2005 Blackwell Publishing Ltd.