Molecular recognition plays an important role in biological systems. Exploiting the complementary base-pairing observed between nucleotides (in DNA and RNA) to build discrete multicomponent composite micelles would be of high value. Herein, we describe the synthesis of short chain block copolymers functionalized with the nucleobase adenine (A) or thymine (T). The copolymers self-assemble in a phosphate buffered aqueous solution and base-pairing is observed between the nucleobase end-functionalized block copolymer and the free nucleobase despite the highly competitive aqueous environment. This phenomenon is only observed when the nucleobase is attached to the hydrophilic end of the copolymer. Exposure to elevated temperatures destroys the hydrogen bonding (H-bonding) between the nucleobase end-functionalized block copolymer and the complementary nucleobase, thus releasing A or T from the micelle. The molecular recognition properties exhibited by these structures have the potential to build higher ordered structures and furnish nucleobase or DNA containing nanomaterials.