This mini-review by Hohl and Dolcos examines the conceptualizations and assessment approaches for cognitive flexibility (CF), a dynamic process that allows individuals to adapt their thinking and behavior in response to changing contextual demands. The review highlights the lack of a unified conceptualization and operationalization of CF within the field, suggesting the need for a more consensual and consistent approach. The authors propose an integrative behavior-brain-context approach to advance understanding of CF. CF is defined as a property that emerges from optimal interactions among several cognitive and neural mechanisms, enabling flexible adjustment of thoughts and behaviors to changing environmental demands. The review discusses three main types of approaches for assessing CF: neuropsychological tasks, self-report questionnaires, and neuroscientific approaches. Each method has its strengths and limitations, and recent evidence suggests that these methods are only weakly associated or not even associated with each other, highlighting the need for a more integrated framework. Neuropsychological tasks assess changes or switches in cognition and behavior in response to changing environmental contingencies, while self-report questionnaires assess changes in thoughts and behaviors or the ability to generate alternatives. Neuroscientific approaches, such as functional MRI, electrophysiological techniques, and optical imaging, identify the brain mechanisms underlying CF. These methods complement neuropsychological and self-report measures, providing insights into the neural substrates of CF. The review also discusses CF interventions, noting that interventions targeting CF can improve executive functions but often show limited transfer to other cognitive or daily life skills. The authors recommend using multimethod approaches to capture the multiple components of CF and promote new insights across various domains of functioning. They conclude that a comprehensive assessment of CF, combining neuropsychological tasks, self-report questionnaires, and neuroscientific approaches, is essential for fully understanding CF as a unified psychological construct.This mini-review by Hohl and Dolcos examines the conceptualizations and assessment approaches for cognitive flexibility (CF), a dynamic process that allows individuals to adapt their thinking and behavior in response to changing contextual demands. The review highlights the lack of a unified conceptualization and operationalization of CF within the field, suggesting the need for a more consensual and consistent approach. The authors propose an integrative behavior-brain-context approach to advance understanding of CF. CF is defined as a property that emerges from optimal interactions among several cognitive and neural mechanisms, enabling flexible adjustment of thoughts and behaviors to changing environmental demands. The review discusses three main types of approaches for assessing CF: neuropsychological tasks, self-report questionnaires, and neuroscientific approaches. Each method has its strengths and limitations, and recent evidence suggests that these methods are only weakly associated or not even associated with each other, highlighting the need for a more integrated framework. Neuropsychological tasks assess changes or switches in cognition and behavior in response to changing environmental contingencies, while self-report questionnaires assess changes in thoughts and behaviors or the ability to generate alternatives. Neuroscientific approaches, such as functional MRI, electrophysiological techniques, and optical imaging, identify the brain mechanisms underlying CF. These methods complement neuropsychological and self-report measures, providing insights into the neural substrates of CF. The review also discusses CF interventions, noting that interventions targeting CF can improve executive functions but often show limited transfer to other cognitive or daily life skills. The authors recommend using multimethod approaches to capture the multiple components of CF and promote new insights across various domains of functioning. They conclude that a comprehensive assessment of CF, combining neuropsychological tasks, self-report questionnaires, and neuroscientific approaches, is essential for fully understanding CF as a unified psychological construct.