The room‐temperature Corbino magnetoresistance (&Dgr;R/R0)cof electron beam zone‐recrystallizedn‐type InSb films tends toward saturation in magnetic fields greater than 3 kOe. This fact as well as the presence of a large magnetoresistance (&Dgr;&rgr;/&rgr;0)Pobserved on long rectangular specimens (l/w>3) are interpreted in terms of a surface layer having a higher impurity concentration and lower electron mobility than the rest of the film. The experimental observations on zone‐recrystallized as well as dendritic InSb films is shown to be consistent with a model of two superposed layers, one with surface‐like and the other with bulk‐like electrical and galvanomagnetic properties.