Information Technology (IT) diffusion is a central theme of the new economy and is evidenced through a process, named Informatization, which permeates our society and businesses. Relative to businesses, managers have a need for instruments to evaluate the organizational use of IT and inform them about its possibilities. This paper presents a tool for evaluating the organizational use of IT based on the measurement of the Informatization Level of companies. Four evaluation dimensions are considered: IT assets; IT organizational use; IT governance; and IT impacts. The tool was built starting with 345 survey questions that were summarized to 66 indicators. A sample of 830 industrial companies was covered and structural equation modeling was employed to develop and validate the model. It achieved requirements of reliability and internal validity and showed external validity, as the hypothesis of being related to size and of not being related to IT investment were confirmed.