Employee portals are utilized by many companies to improve information exchange and communication between their employees as well as to better support business processes. Assessing the benefits of employee portals has become important, owing to limited IT budgets and the need to justify investments in portals. In this paper, we propose a conceptual model for measuring the effectiveness of employee portals on the basis of the DeLone and McLean IS Success Model as well as an extensive review of employee portal success measurement literature. The resulting model is presented as the basis for future empirical work in this area. The development of the survey instrument is described and further validation steps are proposed.