The purpose of this paper is to propose a methodology that evaluates safety management information systems (SMIS) for general contractors mainly in terms of managerial effectiveness. Characteristics and variables of safety management assessments were investigated first, and several assessment techniques were then developed. A single index system measuring safety management performance of projects is also proposed for practical application. The assessments of safety management tasks are performed by several different variables including measures, project lifecycle, organization, etc. The assessment result from a case-company shows that a limited number of safety tasks can effectively represent the overall safety performance of a project. Among these tasks, managing the “daily safety meeting minutes” through the information systems was found to be the most important task. Details and implications of a case are outlined.