To achieve a qualitative understanding of the heteroepitaxial perovskite film formation process, the synthesis and characterisation of La0.6Ca0.4CoO3 nanoscopic islands, ultrathin and thin films is described. These samples are produced by pulsed reactive crossed-beam laser ablation on single crystalline MgO substrate materials. Atomic force microscopic (AFM) and electron microscopic (EM) studies on the very initial growth steps on MgO reveal a three-dimensional (3D) growth mode forming 2 nm diameter perovskite-type islands. After further deposition the islands agglomerate to epitaxial dense films of a cubic perovskite-type metal oxide phase. (C) 2003 Elsevier B.V. All rights reserved.