BACKGROUND: The strength of and relationship between the fundamental elements context, evidence and facilitation of the PARIHS framework are proposed to be key for successful implementation of evidence into healthcare practice. A better understanding of the presence and strength of contextual factors is assumed to enhance the opportunities of adequately developing an implementation strategy for a specific setting. A tool for assessing context-The Context Assessment Index (CAI)-was developed and published 2009. A Swedish version of the instrument was developed and evaluated among registered nurses. This work forms the focus of this paper. PURPOSE: The purpose of this study was to translate the CAI into Swedish, adapt the instrument for use in Swedish healthcare practice and assess its psychometric properties. METHODS: The instrument was translated and back-translated to English. The feasibility of items and response scales were evaluated through think aloud interviews with clinically active nurses. Psychometric properties were evaluated in a sample of registered nurses (n = 373) working in a variety of healthcare organisations in the Stockholm area. Item and factor analyses and Cronbach's alpha were computed to evaluate internal structure and internal consistency. RESULT: Sixteen items were modified based on the think aloud interviews and to adapt the instrument for use in acute care. A ceiling effect was observed for many items and the originally identified 37 item five-factor model was not confirmed. Item analyses showed an overlap between factors and indicated a one-dimensional scale. DISCUSSION: The Swedish version of the CAI has a wider application than the original instrument. This might have contributed to the differences in factor structure. Different opportunities for further development of the scale are discussed. CONCLUSIONS: Further evaluation of the psychometric properties of the CAI is required.