Background: Cognitive Fusion (CF) is a psychological problem that is a fundamental concept within Acceptance and Commitment Therapy. The Cognitive Fusion Scale (CFS), which is used to measure this concept, has not been adapted or validated in Cuba. Objective: To evaluate the psychometric properties of the CFA in adults with anxiety symptoms. Method: Qualitative and quantitative techniques were combined: Expert interview, correlation and concordance coefficients and factor analysis.  Result: The CFQ was adapted from a linguistic and cultural perspective. Nine experts were consulted and consensus was assessed using the content validity coefficient of appropriateness (0.97). During piloting with 35 people, the test achieved a Cronbach's α coefficient (0.927). When the adapted test was applied to 106 adults with anxiety symptoms, a Cronbach's α coefficien...