Bragg scattering of X-ray radiation in a highly asymmetric geometry from Langmuir-Blodgett films was investigated. A complex multipeak structure was observed in the angular distribution of the scattered X-rays. The proposed simple explanation and the corresponding expressions for the peak positions are in good agreement with the experimental results. The same interpretation is successfully applied to experimental results for multilayer films of a quite different origin, the crystalline W/Si superstructures. Based on this agreement and the generalization of the results obtained we propose a new method of monitoring of angular distribution of X-rays propagating in the film at very small angles. Combined with the expressions obtained, it can be applied, in particular, to the determination of the critical angle of total external reflection from multilayer films which provides additional information compared with a conventional technique. Possibilities to study film imperfections are also outlined.