This paper discusses the development of a virtual reality (VR) interface for the visualization of Computational Fluid Dynamics (CFD) data. The application, VR-CFD, provides an immersive and interactive graphical environment in which users can examine the analysis results from a CFD analysis of a flow field in three-dimensional space. It has been tested and implemented with virtual reality devices such as the C2, head mounted display (HMD) and desktop VR. The application is designed to read PLOT3D structured grid data and to display the flow field parameters using features such as streamlines, cutting planes, iso-surfaces, rakes, vector fields and scalar fields. Visualization Toolkit (VTK), a data visualization library, is used along with OpenGL arid the C2 VR interface libraries, to develop the application. Analysts and designers have used VR-CFD to visualize and understand complex three-dimensional fluid flow phenomena. The combination of three-dimensional interaction capability and the C2 virtual reality environment has been shown to facilitate collaborative discussions between analysts and engineers concerning the appropriateness of the CFD model and the characteristics of the fluid flow.