Full-field, time-resolved, velocity vector information was obtained for an opposing jet reactor. The velocities were measured by particle tracking velocimetry (PTV) over a range of jet Reynolds numbers (200-5000). The main results reported are for a Reynolds number of 200. Graphical representation of the extensive data fields cannot be conveniently reported here; however, examples are provided. A more thorough presentation is possible by using color and dynamic representations and these are provided at the URL (Uniform Resource Locator, i.e., the address for a location on the Internet) cited in Zhao and Brodkey (1998). It is important to emphasize that the velocity fields presented in this paper are experimental.