Background: Short and valid instruments for measuring factors facilitating or hindering implementation efforts are called for. This article describes (1) the adaptation of a shorter version of the Evidence-based Practice Attitude Scale (EBPAS-50 items), and (2) the psychometric properties of the shortened version in both US and Norwegian data. Methods: The US participants were mental health service providers (N = 418) recruited from clinics providing mental health services in San Diego County, California. The Norwegian participants were psychologists, psychiatric nurses, and psychology students (N = 838) recruited from the Norwegian Psychological Association and the Norwegian Nurses Organization. A confirmatory factor analysis (CFA) approach was used. Results: The reduction resulted in 36 items named EBPAS-36, and the original 12 factor model was maintained. The EBPAS-36 had acceptable model fit, as indicated by a low degree of misspecification errors in both the US (RMSEA =.045 (CI90%.040-. 049); SRMR =.05) and the Norwegian data (RMSEA =.052 (CI90%.047-. 056, SRMR =.07). Incremental model fit was fair in the US (CFI =.93, TLI =.91) and in the Norwegian samples (CFI =.91, TLI =.89). The internal consistency (Cronbach's a) in the US and the Norwegian samples were good for the total EBPAS-36 score (. 79 and.86, respectively) and were ranged from adequate to excellent for the subscales (US.60-. 91 and Norway.61-. 92). Conclusions: The EBPAS-36 has adequate psychometric properties both in US and Norwegian samples, hence indicating cross-cultural validity. It is a brief, pragmatic, and more user-friendly instrument than the EBPAS-50, yet maintains a broad scope by retaining the original 12 measurement domains.