The advent of low energy-consumption Graphics Processing Units (GPUs) [1] has boosted the graphics capabilities of mobile devices, opening the door to the development of interactive 3D applications that were inconceivable just a few years ago [2]. The mobile market is strongly competitive, and an attractive visual interface is an important advantage in creating a successful device. As a result, mobile device manufacturers have rapidly adopted this new hardware, and the market is demanding new applications featuring advanced 3D graphics and interactive virtual worlds. This scenario opens a wide and interesting research area. Virtual reality applications, until now limited to desktop computers, can now take full advantage of the unique attributes provided by mobile computing: ubiquity, connectivity, context-awareness, and multimodal interfaces. However, these advantages come at a cost. By definition, mobile devices must be small and powered by batteries. These two factors severely limit both their computing power and graphics capabilities. As applications require the handling of larger and more complex 3D scenes, more intelligent and power-efficient techniques will be required. In addition, the nature of handheld devices raises new unprecedented usability issues. The small display sizes, coupled with the limited input technologies, motivate the study of new ways of interacting with the 3D applications. The goal of this theme issue of Personal and Ubiquitous Computing is to investigate the implications of adopting 3D graphics and virtual environments in the field of mobile computing. The papers collected in this issue present current research efforts and useful applications that employ 3D graphics with particular focus on addressing the unique features of mobile devices. Submissions to this theme issue came from an open call for papers. We selected five papers to publish after two rounds of rigorous reviews. A large number of reviewers assisted us in the review process. In order to ensure high reviewing standards, three to four reviewers evaluated each paper.