An asymmetric cryorolling technique was used to reduce the thickness of an Al–Mg–Si alloy sheet from 1.5 mm to 0.19 mm. The samples were subsequently aged for 48 h at 100 °C. The hardness and tensile strength of both rolled and aged sheets increased with the number of passes up to the sixth pass, but the tensile stress decreased after the seventh pass. Investigation of the microstructure of the sheets showed that the grain size after seven passes was about 235 nm and revealed the presence of Fe–Cr–Mn–Si particles in the samples. The deformation of Fe–Cr–Mn–Si particles and sheet thickness affects the ductility when the sheet thickness is less than 0.4 mm, and the strength when the thickness is less than 0.2 mm.