In recent years, there has been a slow but steady advance in the use and the technology of acoustical holography. The major use for this imaging method is in the non-destructive evaluation of thick materials used in the nuclear industry. The most recent advances in-volve the use of linear transducer arrays and computer reconstruction. The former enables the data to be gathered at high speeds and the latter provides aberration-free imaging, as well as pre-and post-processing of the data. In this paper, we describe these advances and show some experimental results.