The crystallization behavior and morphological patterns of a miscible blend of two propylene/ethylene (P/E) copolymers that differed in ethylene content were studied. Metal locene-catalyzed P/E copolymers containing 3.1 and 11.0 mol% ethylene were chosen for blending. The difference in ethylene content was small enough to ensure miscibility of the pair in the melt, and the ethylene content was low enough to ensure that both were crystallizable. The blends were characterized by differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD), optical microscopy (OM) and atomic force microscopy (AFM). The complex melting endotherm of the blends consisted of a broad low temperature peak at T-m1, a high temperature peak at T-m2, and an intermediate peak at T'(m) which was not characteristic of either constituent and depended on blend composition. The multiple melting peaks arose from distinct crystal populations. All the blends exhibited a mixed morphological texture of alpha-radial lamellae with short, densely packed gamma-overgrowths, interspersed with areas of alpha-crosshatch. The high temperature peak at T-m2 was assigned to the melting of the alpha-radial lamellae which formed from chains of the lower comonomer constituent. The broad low temperature peak at T-m1 was attributed to the melting of gamma-crystal overgrowths on the radial lamellae. The new peak at T'(m) was thought to arise from the melting of the alpha-crosshatch lamellae. The lamellar thickness, and hence T'(m), correlated with the crystallization temperature, which decreased as the blend was made richer in the higher comonomer constituent. (c) 2006 Elsevier Ltd. All rights reserved.