The use of renewable feedstock has been a major subject of recent research activities, as industry seeks to develop sustainable environmental practices. The plastics industry can benefit by using renewable feedstock in the form of chemicals, fibers, or fillers. Byproducts of crops like wheat, soy, or corn can be used as fillers in the automotive, packaging, and construction sectors. This presentation will discuss recent advances in the development of agricultural fillers, which represent an opportunity for both environmental and economical sustainability. Several methodologies are being investigated in order to identify materials with the right balance of properties and cost. Manufacturing the filler includes harvesting at the farm, drying, particle-size reduction, and transportation to the compounder. Then, formulation and processing conditions play important roles in determining the final physical properties.