In this work, ultrathin titanium silicide layers were grown on Si(1 1 1) substrates, with the aim to stimulate spontaneous growth of nanostructures by self-assembly. Scanning tunneling microscopy was used as a primary tool for a close, in situ monitoring of the related surface processes. This method enabled a detailed observation of the formation and subsequent evolution of the silicide nanoislands as a function of deposition parameters and annealing treatments. Nanoisland shape and, possibly, phase transformations were analyzed in real time and space with atomic, or near atomic resolution. The results of these measurements are discussed, and plausible explanations offered. (C) 2004 Elsevier B.V. All rights reserved.