The Acceptance and Action Questionnaire (AAQ-II) aims to measure psychological flexibility (PF), described as the ability to act according to chosen values while consciously being in contact with present moment experiences that might function as obstacles. To date, the psychometric properties of a Norwegian translated version of the AAQ-II (NAAQ) have not been published, thus limiting the confidence of findings based on its use with Norwegian samples. The current study sought to address this omission by evaluating the psychometric properties of the NAAQ in a clinical sample (N = 163) with a history of major depressive disorder and residual symptoms of depression. A confirmatory factor analysis supported a unidimensional structure of the scale with good internal (α = 0.87) and satisfactory levels of concurrent and convergent validity. Incremental validity beyond two measures of value-based living was found in predicting depression, anxiety, and three of four domains reflective of quality of life. The overall results support the use of the NAAQ in both research and clinical practice with Norwegian samples.