Objective: The CSQ24 is a shortened version of the Coping Strategies Questionnaire and includes 24 items and four factors-Catastrophizing, Diversion, Reinterpreting, and Cognitive Coping. The factor structure of the CSQ has been a matter for debate for some time. This study aimed to explore the stability of the factor structure of the CSQ24 using repeated measurements in a back pain population at assessment, after physiotherapy treatment, and at 6 and 12 months after treatment. Method: A consecutive sample of 194 adults with chronic low back pain was recruited over 24 months. They completed the CSQ24, with other measures of pain, disability and mood, on 4 occasions. Ninety-six participants satisfactorily completed and returned both 6-and 12-month longitudinal follow-up questionnaires. Results: Exploratory Factor Analysis showed, at each time point, a 4-factor structure of Catastrophizing, Cognitive Coping, Diversion, and Reinterpreting. Within each factor, the factor scores at each time point were significantly correlated and showed good internal reliability. This stability was demonstrated against a background of significant change in measures of pain, disability, and mood. Conclusions: These results provide support for the 4-factor structure of the CSQ24 and its longitudinal stability. Argument is provided for the need to explore the longitudinal stability of related tools in populations that undergo change as a result of treatment.