This study evaluated the psychometric properties of the Codependency Assessment Tool (CODAT) developed by C. Hughes Hammer, D. S. Martsolf. and R. A. Zeller (1998a, 1998b) for Turkish students and investigated the relationship of codependency with attachment styles and family problems. After the translation of the CODAT, Beck Depression Inventory, Experiences in Close Relationships-Revised, and Family Problems of Young Adulthood Evaluation Scale, each was administrated to Turkish female nurse students (n = 400). Factor analysis and Cronbach's alpha values were then computed. Five-factor solution revealed a similar factor structure for the Turkish version of CODAT compared with that of the original tool. Five factors explained 48.38% of the variance. All of the items (with one exception) loaded on their original factors. Cronbach's alpha values for factors ranged between .62 and .78. For the total score, Cronbach's alpha was found to be .75. After statistically controlling for the effects of depressive symptoms, analysis of covariance (ANCOVA) was conducted to investigate if the attachment styles and family problems would change depending on codependency levels. For ANCOVAs, CODAT scores were treated at three levels. Students with higher CODAT scores had more attachment-related anxiety and reported more family problems after controlling for the effects of depressive symptoms. Our research results support the internal consistency and validity of the Turkish version of CODAT. (C) 2009 Elsevier Inc. All rights reserved.