A versatile approach to control the localization of cellulose nanocrystal (CNC) in PLA/PA11 blends is presented. A PEO/CNC mixture with a high level of CNC dispersion is prepared through a combination of high pressure homogenization and freeze-drying. The prepared PEO/CNC mixture is then incorporated into the PLA/PA11 blends using two different strategies. Typically for CNC/PLA/PA11, the CNCs selectively localize in PA11. However, PEO-coated CNC particles segregate into PLA irrespective of whether the PEO/CNC mixture is premixed with PLA or PA11. It is suggested that a strong interaction between PEO and CNC particles combined with the PLA/PEO miscibility facilitates the localization of PEO-coated CNC in the PLA. The localization of PEO-coated CNC in the PLA has no effect on the morphology of the PLA-5PEO/PA11 with matrix/dispersed phase form. However, 2 wt % PEO-coated CNC in the co-continuous (PLA-5PEO)/PA11 50/50 vol % blend diminishes the phase thickness from 11 +/- 1 to 4 +/- 1.5 m. This is attributed to a retarded relaxation of the PLA phase. This work outlines a strategy to control the CNC localization into a given polymeric phase in a binary polymer-polymer mixture. (c) 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 576-587