The Langmuir-Blodgett technique has been used to fabricate polar (Z-type) amphiphilic azobenzene-derivative ultrathin films. The UV-visible spectra indicate the existence of H-like aggregation in the film. The X-ray diffraction spectrum shows two series of independent peaks which correspond to double long spacings of 3.1 nm and 3.5 nm, respectively. The linear dichroic FTIR spectra and the special character of the molecule itself give additional information on the film structure. A staggered aggregation structure of the films may be inferred from the results.