A method to describe froth stability in industrial flotation cells, and its link with froth recovery, is discussed in this paper. The direct measurement of froth stability in industrial flotation cells is still controversial, and different techniques have been developed. In this paper, the froth half-life time and bubble size on the top of the froth are discussed as indicators for froth stability. Experiences at two flotation concentrators treating porphyry copper ore are compared. The relative contributions to froth stability from frother in solution and solids loading in the froth were investigated in both concentrators, and links were found between both the froth half-life and bubble size on the top of the froth and the amount and nature (hydrophobicity) of particles in the concentrate. The comparison also suggests how two significantly different operating strategies for the froth phase may lead to similar outcomes in terms of froth recovery. (c) 2008 Elsevier B,V. All rights reserved.