Numerous non-ionic thermally responsive homopolymers phase separate from their aqueous solutions upon heating. Far fewer neutral homopolymers are known to phase separate upon cooling. A systematic compilation of the polymers reported to exhibit thermoresponsive behaviour is presented in this review, including N-substituted poly[(meth)acrylamide]s, poly(N-vinylamide)s, poly(oxazoline)s, protein-related polymers, poly(ether)s, polymers based on amphiphilic balance, and elastin-like synthetic polymers. Basic properties of aqueous solutions of these polymers are briefly described.