BACKGROUND: Computer-assisted surgery (CAS) systems are currently used in only a few surgical specialties: ear, nose and throat (ENT), neurosurgery and orthopaedics. Almost all of these systems have been developed as dedicated platforms and work on rigid anatomical structures. The development of augmented reality systems for intra-abdominal organs remains problematic because of the anatomical complexity of the human peritoneal cavity and especially because of the deformability of its organs. The aim of the present work was to develop and implement a highly modular platform (targeted for minimally invasive laparoscopic surgery) generally suitable for CAS, and to produce a prototype for demonstration of its potential clinical application and use in laparoscopic surgery. METHODS: In this paper we outline details of a platform integrating several aspects of CAS and medical robotics into a modular open architecture: the EndoCAS navigator platform, which integrates all the functionalities necessary for provision of computer-based assistance to surgeons during all the management phases (diagnostic work-up, planning and intervention). A specific application for computer-assisted laparoscopic procedures has been developed on the basic modules of the platform. The system provides capabilities for three-dimensional (3D) surface model generation, 3D visualization, intra-operative registration, surgical guidance and robotic assistance during laparoscopic surgery. The description of specific modules and an account of the initial clinical experience with the system are reported. RESULTS: We developed a common platform for computer assisted surgery and implemented a system for intraoperative laparoscopic navigation. The preliminary clinical trials and feedback from the surgeons on its use in laparoscopic surgery have been positive, although experience has been limited to date. CONCLUSIONS: We have successfully developed a system for computer-assisted technologies for use in laparoscopic surgery and demonstrated, by early clinical trials, that the introduction of these technologies in operative laparoscopy, even though they are not yet sufficiently accurate (from an engineering viewpoint) for surgical treatment of intra-abdominal disease, brings added benefits to the execution of interventions by surgeons and hence represents concrete on-going progress in interventional technology.