An optical technique for evaluating Young's modulus of a vibrating cantilever beam is presented. The technique utilizes two charge-coupled device (CCD) cameras to record and process the images of a vibrating beam. Equations relating the natural frequency with the imaging time are obtained, and Young's modulus as a function of the natural frequency is subsequently determined. The Young's modulus values are compared with those obtained using the conventional strain gauge method. The results show good agreement. The proposed technique is relatively simple and could be used to determine the Young's modulus of a wide variety of beam materials.