There is an ongoing project on the University of Porto (U. PORTO) that aims the association of two didactical tools of information and communication technologies: eLearning and computer-based assessment (CBA). Implementing CBA at an institutional level raises several issues. Supporting staff, if existing, have to address and solve some hard challenges: pedagogical training in new assessment methods, technical problems in the implementation process and organizational problems. These last are particularly complex in a university campus like U. PORTO: large and spread. The e-Assessment topic is of general interest for those who work in eLearning, specially now in the era of Web 2.0, where many questions arise due to so many different approaches of methodology, strategies and evaluation. U. PORTO is no exception. The need of being more accurate in the assessment process when using the web, even if the teachers use a blended-learning approach, is real and work is being developed in order to try to respond to this need. Although the eLearning Unit (GATIUP) works towards different assessment methods, this particular paper focus on the implementation of online tests on campus using the University LMS - Moodle. We will explore the experience acquired in implementing large scale high stake examinations in different faculties: Pharmacy, Economics, Medicine, Dentistry, Humanities. On the school year of 2008/2009, 1548 students did their high stake exams online; in 2009/2010 only in the first semester 869 students were evaluated and graded on Moodle. Also, test analysis has been conducted with interesting information about the items and the quality of the overall exam. It will also be presented the strategies that U. PORTO is engaging to overcome some of the difficulties found in the implementation of such project.