Assessment of nursing informatics competencies has gained momentum in the scholarly literature in response to the increased need for resources available to support informatics capacity in nursing. The purpose of this study was to examine the factor structure and internal consistency reliability of the Canadian Nurse Informatics Competency Assessment Scale, a newly developed 21-item measure based on published entry-to-practice informatics competencies for RNs. For this study, 2844 nurses completed the Canadian Nurse Informatics Competency Assessment Scale through a cross-sectional survey. Exploratory principal component analysis with oblique promax rotation revealed a four-component/factor structure for the 21-item Canadian Nurse Informatics Competency Assessment Scale, explaining 61.04% of the variance. Item loading per each component reflected the original Canadian Association of Schools of Nursing grouping of nursing informatics competency indicators, as per three key domains of competency: information and knowledge management (α = .85); professional and regulatory accountability (α = .81); and use of information and communication technology in the delivery of patient care (α = .87) with the exception of one item (Indicator 3), which loaded into the category of foundational information and communication technology skills (α = .81). This study provided preliminary evidence for the construct validity of the entry-to-practice competency domains and the factor structure and reliability of the Canadian Nurse Informatics Competency Assessment Scale among practicing nurses. Further testing among nurses in other settings and among nursing students is recommended.