The growth of platinum on a MgO(0 0 1) substrate was studied for various deposition temperatures between 250degreesC and 1000degreesC. The epitaxial growth and surface morphology were investigated using RHEED, atomic force microscopy, X-ray diffraction and high resolution transmission electron microscopy. When deposited at low temperature (< 500degreesC), the Pt presents a quasi 2D growth in the [I 1 1] direction while 3D islands were obtained for a higher growth temperature. In that case, [00 1] and [I 1 1] growth directions have been evidenced leading to different polyhedral structures for the two types of Pt islands. (C) 2003 Elsevier Science B.V. All rights reserved.