The interphase region in an epoxy-aluminum adhesive bond has been micromechanically characterized using a new acoustic microscope which employs a coupling fluid with a low speed of sound. A V(z) curve fitting method was used to calculate the property profiles across the interphase. The interphase region appeared to have shear and longitudinal wave speeds which were, on average, 14% and 11% larger than those of the bulk adhesive, respectively. The average interphase density was 5.5% smaller than the bulk density. The results were in conformity with a previous microscopic and nano-indentation study on the same adhesive system.