The adhesion of polystyrene latex (PSL) particles to cotton fibers was investigated in aqueous sodium alkylate solutions. The PSL particles were polymerized in a surfactant-free system. The sodium alkylates used were sodium octanoate, sodium decanoate, and sodium dodecanoate. The number of particles adhering to the cotton fibers from an aqueous suspension containing sodium alkylate was determined spectroscopically. The rate constant of particle adhesion and the apparent equilibrium amount of the PSL particles adhering to the fibers were obtained. The total potential energies of interaction between the particle and fiber were calculated using the electrokinetic potentials and the thickness of the adsorbed layer on the basis of the heterocoagulation theory. A plot of the logarithmic rate constant of adhesion against the maximum potential energy was found to be linear. The relation between the equilibrium amount of adhesion and the depth of the primary well was also linear. The adhesion of PSL particles to cotton fibers in aqueous sodium alkylate solutions was interpreted in terms of the total potential energy, which was calculated by considering the existence of an adsorption layer.