In recent years, adult attachment styles (secure, fearful, preoccupied, and dismissing) have been widely investigated within the framework of four-category model (Bartholomew and Horowitz, 1991). In three consecutive studies, the reliability and validity of two commonly used measures of attachment styles were examined on the Turkish sample and a cross-cultural comparison with a U.S. sample was made. Results of the Study I revealed that both the single and multi-item measures of attachment styles (Relationships Questionnaire; Re and Relationships Scales Questionnaire; RSQ) have satisfactory level of reliability, stability and convergent validity. However these two measures did not correspond bl classifying respondents into the four attachment groups in an acceptable degree. Study 2, first, replicated the results of study I and second, demonstrated that the four attachment styles can be sufficiently identified among Turkish students. Supporting the construct validity of the attachment scales, findings indicated that the four attachment styles were organized around the two underlying dimensions of attachment (models of self and others), and they were related to the outcome variables employed in the study consistent with the assumptions of attachment, theory. The final study permitted a comparison of Turkish sample with American students from the perspective of four- category model. It was found that although the attachment scales had compatible psychometric quality in both cultures, the RSQ was relatively more consistent than the Re across the two samples. Furthermore, cultural differences in attachment styles were found especially among the insecure styles and students with preoccupied styles in the Turkish sample and those with dismissing and fearful styles in the American sample seemed to be overrepresented Findings were discussed in the light of attachment literature regarding the measurement issues and cross-cultural differences.