There have been few evidence-based assessments of nursing education core curricula. To conduct such assessments effectively, researchers need an objective professional tool that addresses the principal competencies of the nursing profession. The aim of this study was to develop a preliminary assessment tool to improve teaching effectiveness in nursing core curricula. This study was divided into four stages: (a) initial questionnaire content proposal, (b) expert validation, (c) random sampling, and (d) item and exploratory factor analysis. We used exploratory factor analysis to analyze three factors, namely (a) learning preparation, (b) advancement of competence, and (c) learning evaluation. These three factors explained, respectively, 43.1%, 12.9%, and 7.5% of total variance; the three together explained 63.5% of total variance. Overall questionnaire reliability was .904. All correlation coefficients displayed moderately positive relationships among subscales. The assessment tool developed in this study showed reliability and validity in the evaluation of teaching outcomes for nursing core curricula.