Following on from the study by Brevdo and Merkine (1985), this paper examines the nature of boundary-layer separation in the two-layer flow past a cylinder in a rotating frame for the zero Froude number case and makes a comparison with that study. The full equations are solved numerically for the steady laminar flow throughout the region and then compared with the results of the study of Brevdo and Merkine, which solved the boundary-layer equations. This includes a comparison of radial-velocity profiles, cylinder shear stress and separation criteria. Good agreement was found between the two studies when the flow in the faster layer had not separated, however, the model of Brevdo and Merkine was no longer appropriate once the flow in the faster layer had separated. An interesting feature of this flow is that the flow in the slower layer can be reversed without separation taking place.