The effects of a range of nonionic and ionic water-soluble polymers on the micellar stability of sodium dodecyl sulfate were investigated by the pressure-jump method. The presence of polymer that interacts with SDS was found to decrease the micellar stability drastically. Surface activity of the polymers was correlated with their ability to reduce the micellar stability. The decrease in micellar stability was explained by the formation of premicellar aggregates (or submicelles) of surfactants in the presence of polymer, which facilitated the micelle formation-disintegration process.