Abstract : The study of reverberation is well known to be a very complex one with many competing mechanisms seen in real data (see Fig. 1). Much progress has been made in our understanding of reverberation (see for example ONR sponsored Acoustic Reverberation Special Research Program (ARSRP) and Critical Sea Test (CST) program publication lists and the abstracts and reference list for this workshop). However, there remain important unanswered questions and a real scarcity of high-quality basic research data sets. For example, Fig. 2 shows the large spread in some typical shallow water bottom scattering strength estimates but in most cases not enough supporting measurements were taken to rule out competing mechanisms like surface or volume scattering at low grazing angles. To address this important problem, the ONR Ocean Acoustics Program held a Shallow- Water Reverberation Focus Workshop on August 25, 26, and 27, 1999 in Santa Fe, New Mexico. The primary objective of the workshop was to convene a small group of leading scientists in the area of acoustic reverberation to identify current scientific issues related to shallow-water reverberation, scattering mechanisms, and associated reverberation experiments. The key focus was on bottom reverberation and bottom scattering. In particular, the workshop emphasis was on the definition of goals for current and future ONR shallow-water reverberation projects and issues related to the development of reverberation models and experimental designs. The frequency range of interest for this workshop was for the band from - 50 Hz - 6 kHz. The upcoming US-Asia experiment was an important topic of discussion during the latter part of the workshop.