The froth phase is one of the main components of froth flotation as it defines both the quality of the end product and overall efficiency. The performance of the froth depends on a number of sub-processes that interact in very complex ways, and it is a great research challenge to explicitly name the role of each of these sub-processes. This paper provides a summary of recent studies of flotation froths. The key physical processes operating in the froth are reviewed, and their effect on the behaviour of froth is discussed. The findings in the literature relevant to froth stability are also highlighted in the context of flotation froths. (C) 2011 Elsevier B.V. All rights reserved.