Formation of gas hydrates is a problem in the petroleum industry, where the gas hydrates can cause blockage of the flowlines. Kinetic hydrate inhibitors (KHIs) are water-soluble polymers that are used to prevent gas hydrate blockages, and they have been used in the field successfully. In this paper we present the first KHI performance results of a series of polymers containing pendant carbamate groups, poly(hydroxyl-N-alkylcarbamate)s. Similar polymers have been investigated as KHIs before, some of which have been commercialized. Hydroxyalkylcarbamates with varying alkyl pendant groups from methyl to iso-butyl are reported. It was found that increasing the pendant alkyl chain and branching gave increasing KHI performance; however, the polymer also became significantly less soluble in water or had a very low cloud point temperature (TCl). Both solubility and TCl were slightly improved by copolymerization, and we found that the copolymer with pendant iso-butyl- and methylcarbamate 2:1 and 3:1 gave the best ...