The growth kinetics of deposited gold atoms on the surface of highly oriented pyrolytic graphite can be controlled by modification of the graphite surface by a single layer of zinc porphyrin trimer molecules. Densely packed nanocluster films (see Figure (200 nm x 200 nm)) result, rather than the open, fractal structure produced on the bare graphite surface. No permanent defects are produced in the substrate surface and the molecules can be removed following metal deposition.