A number of polyurethane anionomers based on isophorone diisocyanate, polytetrahydrofuran, and cyclohexane dimethanol were prepared as aqueous dispersions. The dispersions were stabilized by the use of an internal emulsifier. The principal ionic moiety used was dimethylol propanoic acid, but dimethylol butanoic acid and an experimental suphonate diol sodium salt were also used. The consequence of the neutralization step, the degree of neutralization, the type of ionic component, and the type of counterion were investigated for their effect on the mechanical and colloidal properties of the polyurethanes. Dynamic mechanical thermal analysis, tensiometry, solvent spot testing, and swelling studies were used for the characterization of the materials.