Optical rheometric methods are being used in this project to characterize the structure and dynam- ics of suspensions during flow. The methods being employed are primarily scattering methods: scattering dichroism and small angle light scattering. These are being applied to a wide range of problems that include: (1) determinations of the aspect ratio of colloidal particles, (2) flow induced structure in strongly flocculated suspensions, (3) orientation dynamics of a concentrated nematic suspension, and (4) the influence of interparticle interactions on the microrheology of dense suspensions. The platform for these measurements is a newly developed facility based upon the principle of light transmission at oblique angles of incidence within a commercial stress rhe-ometer.