Sonochemistry in now well recognized as a technique for the fabrication of nanomaterials. This is reflected in the many review articles that have been published over the last few years. Suslick, one of the forefathers of this field, has written a very comprehensive review on this topic (Beng, 2010) and he has summarized the work published until 2010. The current review will scan the work done in sonochemistry until the end of 2012. The current review will concentrate first on explaining why nano. Namely, when, why, and what kind of nanomaterials are produced upon the collapse of the acoustic bubble?