From results of adsorption studies of aqueous bis(triethanolammonium) 1,10-decanedicarboxylate on magnetite, a three-stage model for the process of adsorption of the anionic surfactant is suggested. At low concentrations adsorption occurs as a result of electrostatic interactions between positively charged surface sites and anionic dicarboxylates in solution. As the lowest concentration for aggregate formation in solution is approached, an observed first plateau in the adsorption isotherm is believed to be associated with aggregation in the plane of the surface with surfactants adsorbed horizontally and with both polar moieties attached to the surface. Shielding of surface sites by adsorbed anions and space requiring amine sequestering of surface metal ions are suggested as possible reasons for the relatively low adsorption density characterizing the first adsorption plateau. The dramatic change in adsorption above a certain critical concentration may be explained by a conformational transition, by which the adsorbed difunctional compound assumes an upright position with only one point of attachment to the surface. Experimental data indicate that the carboxylate moiety extending into the bulk solution is closely associated with a triethanolammonium ion. The strong cooperativity characterizing initial third stage adsorption may partly result from previously covered surface sites becoming available as a result of the change in conformation of adsorption. The second plateau in the adsorption isotherm coincides with a second aggregational transition in solution. Estimated surface charge conditions are used to discuss amine adsorption mechanisms. A comparison between results of fitting the present adsorption data to an equilibrium adsorption model and a semiempirical model, based on complete surface coverage with horizontally oriented surfactants as a prerequisite for incipient stage three adsorption, favors the latter model. It is also inferred that literature data from a study of the adsorption of another type of alpha,omega-surfactants may be accommodated within the present adsorption model, despite considerable differences in experimental conditions.