Objective: To examine the concurrent validity of the Anxiety Symptom-scale against two well-being scales, the Cantril Ladder (CL) and World Health Organization Well-Being Index (WHO-5), to test the algorithm defining anxiety against these scales, and identify cut-off points for the Anxiety Symptom-scale sum score. Subjects: 14,405 adult respondents completing all psychometric questions in the Lolland Falster Health Study. Method: Receiver operating characteristic analyses comparing Anxiety Symptom-scale WHO-5 and CL. Results: 2.5% of respondents had an anxiety disorder (3% female and 2% male) according to the Anxiety Symptom-scale algorithm. The area under the curve (AUC) was 0.87 for CL and 0.90 for WHO-5 (using inverse scores), indicating high concordance with anxiety disorder as identified by the scale. A score solely ≥2 on item 10 is a relevant cut off to low wellbeing. Anxiety disorder covers a broad range on the scale’s sum score, with 3 to 4 indicating low well-being in this population sample and a sensitivity of 0.85 − 0.99 against CL and WHO-5. Conclusion: The Anxiety Symptom-scale is a sensitive and valid instrument for the identification of patients in low well-being with symptoms of anxiety. A score ≥2 on the functional impact (Item 10) of all symptoms is a relevant indicator of anxiety associated with low well-being in this sample. A higher Anxiety Symptom-scale sum score is coherent with lower well-being, though without specific cut-off points. Further validation of the Anxiety Symptom-scale in a clinical setting is recommended.