Objective: Clinical perfectionism is involved in the etiology and maintenance of eating disorders. Limited research has examined the factor structure of the Clinical Perfectionism Questionnaire (CPQ) in clinical eating disorder samples. The aim of this research was to examine the validity and reliability of the CPQ in a mixed eating disorder sample. Method: Patients (N = 211) with an eating disorder completed the CPQ at pretreatment. A bifactor model was tested that included a general clinical perfectionism factor and two group factors; overevaluation of striving and concern over mistakes. The unique contributions that general and group factors make to the prediction of eating disorder symptoms were also investigated. Unidimensional, correlated two-factor, and bifactor models were tested using confirmatory factor analysis. Results: A bifactor structure for a revised 10-item version of the CPQ provided the best fit, with a strong and reliable general clinical perfectionism factor. The general clinical perfectionism factor and the overevaluation of striving group factor explained reliable variance in the CPQ, and but only the general factor predicted eating disorder symptoms. Discussion: The results suggested that a total score is generally appropriate for assessing clinical perfectionism in a clinical eating disorder sample.