A significant proportion of subcutaneous hematomas remain undetected after external visual examination of the body. In the case of a cadaver such hematomas can be easily identified through a cutaneous incision but in living persons the diagnosis becomes more complicated. The usual methods, based on diagnostic imaging, do not combine sufficient reliability and feasibility. The results of our investigations demonstrated that forensic diaphanoscopy is a highly sensitive (95%) and specific (97%) means to determine the presence or absence of subcutaneous invisible hematomas. In addition, it is possible to locate such hematomas with great precision, to draw their shape and evaluate their magnitude. The lower limit of detection is of the order of 1 mm. The advantages of this method lie in the fact that it is reliable, non-invasive, has no side effects, is simple to carry out and allows real time scanning