The purposes of this study were to report on a systematic approach to validating a Spanish version of the Principal Instructional Management Rating Scale and then to apply the scale in a cross-national comparison of principal instructional leadership. The study yielded a validated Spanish language version of the PIMRS Teacher Form and offers a model of scale validation for other scholars who are interested in preparing an instrument for use outside of its culture of origin. The researchers used a back translation and expert panel procedure combined with psychometric analysis in order to achieve cultural equivalency for the translation. Psychometric properties of reliability (G Theory test of reliability) and validity (CFA, Rasch analysis) of the new version were assessed and compared to the original version in order to underpin its validity. The validation study employed a sample of 595 teachers and 26 principals in Santiago, Chile. The study yielded both a comprehensive analytical approach to cultural adaptation of survey instruments, as well a scale that can be used in Spanish speaking contexts. The study further demonstrated variability in patterns of instructional leadership practice across several national contexts.