Dynamic Light Scattering (DLS) is a very effective method of measuring properties of dilute polymer solutions. From correlation of the scattered light one can obtain the diffusion coefficient and effective hydrodynamic radius of the polymer molecules, as well as data on the internal movement of the polymer chain. This study focused on the effects of concentration on the diffusivity and hydrodynamic radius. Systems of varying molecular weight polystyrene in cyclohexane at theta conditions were studied. Through this work, an accurate and reproducible method of obtaining dynamic light scattering (DLS) measurements was established. DLS can be used for future measurements on any polymer in a dilute system.