Virtual environments (VEs), offering a new human-computer interaction paradigm, have attracted much attention, in clinical psychology, especially in the treatment of phobias. However, a possible new application of VR in psychology is as assessment tool: VEs can be considered as an highly sophisticated form of adaptive testing. This chapter describes the context of current psychological assessment and underlines possible advantages of a VR based assessment tool. The chapter also details the characteristics of BIVRS, Body Image Virtual Reality Scale, an assessment tool designed to assess cognitive and affective components of body image. It consists of a non-immersive 3D graphical interface through which the patient is able to choose between 9 figures of different size which vary in size from underweight to overweight. The software was developed in two architectures, the first (A) running on a single user desktop computer equipped with a standard virtual reality development software and the second (B) splitted into a server (B1) accessible via Internet and actually running the same virtual ambient as in (A) and a VRML client (B2) so that anyone can access the application.