The living anionic polymerization of n-hexyl isocyanate (HIC) using a newly developed initiator forming metalenolate complex, sodium deoxybenzoin (Na-DB), is reported. For the polymerization of HIC, Na-DB serves the dual functions of providing controlled fast initiation and efficiently protecting the living chain ends. The use of Na-DB has resulted in quantitative polymer yields (approximate to 100%), effective control of the polymer's molecular weights, and low polydispersity index. To examine the living nature of poly(n-hexyl isocyanate) (PHIC), block copolymerization of HIC with another isocyanate monomer, 3-(triethoxysilyl)propyl isocyanate (TESPI), was carried out. The resulting block copolymer, poly(n-hexyl isocyanate)-b-poly(3-(triethoxysilyl)propyl isocyanate) (PHIC-b-PTESPI) was synthesized successfully via living anionic polymerization using Na-DB with quantitative yield and controlled molecular weight. (c) 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013, 51, 1742-1748