We report for the first time the synthesis and kinetic gas hydrate inhibition of a series of pseudo-polypeptides, poly(N-alkylglycine)s, with varying length alkyl side chains. The polymers have similar molecular weights for performance comparison. Tests were carried out in a multi-cell rocking rig at high pressure using a structure-II-forming natural gas blend. The best polymer tested was poly(N-propylglycine), with the performance being dependent upon the polymer molecular weight and water solubility.