Abstract: A synthetic aperture technique for ultrasonic diffraction tomography has recently been proposed by Nahamoo et al.. The technique has two advantages. First, the object to be imaged needs to rotate only once by 90° in order to collect the scattered data sufficient for its reconstruction. Secondly, by taking into account the aperture functions of the transmitting and receiving transducers, the technique, in principle, permits the use of illuminating waves of any type, as opposed to only plane waves. In this paper, we describe a computer implementation for tomography reconstruction of the ’filtered-backpropagation type for the technique. The implementation is interpolation-free, and the reconstruction of an N×N image is completed using, mainly, 2N FFT operations. Computer simulations are also included.