The constitutive behavior of both direct-chill cast (DC) and continuous cast (CC) AA5754 sheet materials has been investigated up to large strains using a modified shear test. The modified shear sample prevents rotation of the shear zone compared to the ASTM standard B831 test (2005, “Standard Test Method for Shear Testing of Thin Aluminum Alloy Products,” 2005 Annual Book of ASTM Standards, West Conshohocken, PA, Vol. 02.02, pp. 601–603). The results show that the effective stress and effective strain curves from shear tests match those obtained from uniaxial tension, but only by incorporating the material anisotropy using the Barlat–Lian yield function. The flow stresses of both materials saturate at large strains; however, the fracture strain of the CC material is significantly lower than that of the DC material.