Production of corn masa-based products is flourishing in the United States, as is the generation of masa processing waste. Masa by-products have potential for value-added utilization, an option which could produce less pollution in the environment and economic benefits for masa processors. Physical and nutritional properties of these byproducts are needed for the proper design of processing operations and by-product applications, but information concerning masa byproducts is not currently available. Thus the objective of this study was to fully characterize typical masa by-product streams. The masa by-products studied had moisture contents between 88.15% and 89.29% (w.b.), water activity values between 0.999 and 1.000, densities between 1030.85 and 1047.32 kg/m3 , yield stress values between 1440.04 and 1618.08 N/m2 , pH values between 6.17 and 6.30, Hunter L values between 35.15 and 49.13, a values between 0.27 and 0.98, and b values between 6.85 and 9.38. Drying curves were developed to predict drying behavior. The dried by-products had protein contents between 4.76% and 4.90% (d.b.), crude fat contents from 0.74% to 5.76% (d.b.), ash contents between 17.41% and 19.09% (d.b.), and carbohydrate contents from 71.93% to 75.41% (d.b.), which was due primarily to fiber, with hemicellulose levels of 20.82% to 24.06% (d.b.) and cellulose between 30.55% and 31.83% (d.b.). Dry masa by-products also consisted of 4.68% (d.b.) calcium. Therefore, dehydrated masa by-products seem very suitable for use as livestock feed additives.