With recent developments in communication and information technologies, using collaborative virtual environment in design practice has experienced a remarkable increase. Today. those advanced technologies also bring new challenges for design education. Particularly, employing 3D virtual worlds in design teaching, which requires the consideration of new pedagogical approaches, has been accepted and widely practiced. However, there is a general lack of formal evaluation with empirical evidence of the performance of virtual worlds and students' perception of using 3D virtual worlds in design collaboration. The paper starts with a collaborative design studio over Second Life which took place in a virtual island, 'NU Genesis', between the University of Sydney and Rangsit University. The paper presents the design outcomes and an analysis on the result of an inclusive questionnaire completed by the participated students. In this paper, based on the teaching experience in 3D virtual worlds and the results of the questionnaires, the benefits and shortcomings of virtual worlds on collaborative design education have been evaluated.