Conventional techniques for selection of wax inhibitors for crude oils have been limited in that visualizing oil and wax behavior under flowing conditions has not been possible. This paper describes a new technique, videomicroscopy, which allows for visualization of precipitating wax behavior in flowing oil under field conditions. In addition to videomicroscopic data, results of conventional crude oil and model wax systems characterization are given. These conventional techniques include cloud point, pour point, rheology and crystal morphology characterization. Results from videomicroscopy agree with, but go well beyond, what iss learned from conventional analysis. Videomicroscopy shows uninhibited crude to form strong wax aggregates resulting in plug flow, while inhibited oil tends to produce weakly bonded clusters. The technique shows changing behavior of the wax with respect to network formation and deposition as functions of temperature and shear.