This work deals with the characterization of the adhesion quality and of the adhesive film properties in Titanium/Epoxy adhesive film/3D Composite aeronautical assemblies. Due to the thickness of the adhesive film in the different samples, between 60 m and 200 m, the study is performed with a scanning acoustic microscope (SAM) in pulse-echo mode, at high frequencies (30 and 50 MHz). The difficulties expected and that are challenged are both due to the acoustic impedance contrast between the materials and to the high frequency that should make the reflected echo at the Epoxy film-Composite undetectable or in the better way very attenuated. These conditions impose that the experiment must be carried out carefully and with high accuracy. Nevertheless, the observation of the small amplitude reflected echo at the adhesive film-composite interface in the different samples was possible thanks to the good signal-to-noise ratio (SNR) of the experimental set up instrumentation. The properties of the adhesive film are determined and the quantification of the adhesion quality is achieved via an interphase model solved by the Debye Series formalism. Moreover, SAM images are performed and confirm the obtained adhesion quantification and give an approximated and fast estimation of the adhesive film thickness.