Previous self-report measures of attachment have used different assessment approaches, and a common conceptualization is using a dimensional perspective in which attachment is measured with two factors: attachment anxiety and attachment avoidance. The Experiences in Close Relationships—Relationship Structures Questionnaire (ECR-RS) has, prior to this study, been assessed for psychometric properties regarding specific relationships, but not in a shorter version for close relationships in general. In this paper, we present a Swedish translation of the ECR-RS Global nine-item version assessed for factor structure and psychometric properties by using a cross-validation approach with two separate adult samples. In Study 1 (N = 492), participants were randomly split into two subsamples. Using an exploratory factor analysis (EFA), the first subsample was used for finding the best-fitting model while the second subsample was used to test the a priori model using confirmatory factor analysis (CFA). In Study 2 (N = 806), we set out to validate the factor structure yet again by using CFA. Results from the EFA supported a two-factor structure with six items for attachment avoidance and three items for attachment anxiety. In the validation of the factor structure using CFA, both studies showed that all model-fit indices were good only after some modification, including removal of one avoidance item. Methodological reasoning and implications are discussed. The final eight-item model showed good internal consistency, as well as good convergent and discriminant validity, and multi-group invariance tests for gender and age showed no violations to invariance. Findings are encouraging to use this short global attachment self-report instrument, but further validation is advised.