Elements of the technology of nylon fibers and nylon plastics are reviewed. These include the development of equations to quantify the effects of end-group imbalance and chain-ending impurities, the kinetics of the polymerization of caprolactam, the solid-state polymerization of nylon-66, and the dependence of fiber tensile strength on molecular weight. This is followed by remarks that include comments on the significance of the amidation equilibrium for melt behavior and estimates of the activation energy of viscous flow, the pyrolysis of nylon, the use of the glass-transitionb temperature (T-g) to predict the effect of moisture on properties, and the prospect for new nylons.