In the field of particle technology, processes cannot yet be designed from a basic molecular understanding. Nanotechnology, however, begins to bridge this pp between molecules and particles, and may thus not only open new ways for the production and handling of particulate matter, but also for the engineered design of advanced material properties. The visions and applications in nanoparticle technology cover a broad range, e.g. quantum dots in information technology, refractory particles for advanced ceramics, highly active Substances in pharmacy, catalysts and micro- and mesoporous adsorbents to name only a few applications. Starting from the concept of product engineering we investigate the basic preconditions for tailoring nanoparticulate properties, i.e. the control of the particle interactions. This concept is then applied to precipitation as an example for particle synthesis and to particulate thin film formation as an example for structure formation.