Al growth and nucleation on polyimide and the resultant surface morphologies and interfacial structures have been investigated by atomic force microscopy, focused ion beam scanning electron microscopy, Rutherford backscattering spectroscopy, and x-ray photoelectron spectroscopy. Al growth on polyimide proceeds in a two-dimensional-like mode. Initial Al deposition results in the formation of nanoparticles, exhibiting the interface structures arising from the Al interacting with the carbonyl groups of the polyimide. Subsequent Al growth produces a landscape of crystallized islands, and these islands have submicrometer dimensions with different orientations.