Alternating Langmuir-Blodgett films were deposited with two complementary molecules : 5-(4-N,N-dioctadecyl aminobenzylidene)-2,4,6-(1H,3H)-pyrimidinetrione (B) and 4-amino-2,6-didodecylamino-1,3,5-triazine (M). Pressure-area isotherms were recorded. The transfer behavior of the alternating films was compared with that of the separate films of B. X-ray diffraction measurements confirm that the alternating films have a genuinely alternating structure : MBMB...MB. Transmission FTIR measurements reveal that in the separate films B is exclusively self-aggregated through the hydrogen bonding between the C=O and N-H on the barbituric ring of B, and in the alternating films new hydrogen bonds are formed between B and M at the expense of those of the initial self-aggregation. Polarized attenuated total reflectance Fourier transform infrared spectroscopy measurements show that in the alternating films the hydrocarbon chains stand almost vertically, in comparison with the separate films of B as well as of M. It is found that in the alternating films the 2-position carbonyl on the barbituric ring of B is perpendicular to the film plane. It is concluded that the interlayer hydrogen bonding between B and M gives rise to a better film structure.