Research has shown that the manifestation of corporate entrepreneurship is an important strategy for the success of private- and public-sector organizations. The Corporate Entrepreneurship Assessment Instrument (CEAI) is an instrument that was developed to measure the key internal organizational factors that influence a firm's entrepreneurial activities and outcomes. The present research employs three studies to assess the content, construct, and convergent validity of the CEAI using a well-established framework for scale development and refinement. The CEAI was found to be a relatively stable instrument, although the factor structure that emerged varied slightly from the original instrument. In sum, as a result of our analyses, a more parsimonious and psychometrically sound set of items for each factor was derived yielding an 18-item instrument based upon the original 48-item measure. Our studies of the CEAI present a timely contribution toward advancing research in the area of organizational preparedness for corporate entrepreneurship.