Mixed matrix membranes (MMMs) have been prepared by combining a small amount of highly absorbing non-toxic ionic liquid, [emim][Ac] (IL) (5 wt%), a biopolymer from renewable abundant natural resources, chitosan (CS), and nanometre-sized metal-organic framework (MOF) ZIF-8 or HKUST-1 particles to improve the selectivity of the IL-CS hybrid continuous polymer matrix. The TGA revealed that the thermal stability has been enhanced by the influence of both IL and ZIF-8 or HKUST-1 fillers, while keeping a water content of around 20 wt%, which suggests the potential of such materials for developing high temperature water resistant membranes for CO2 separation. The CO2 and N2 single gas permeation performance was tested at temperatures in the range of 25-50 C, to compare with the previously reported IL-CS hybrid membranes. The best CO2 permeability and CO2/N2 selectivity performance is obtained for 10 wt% ZIF-8 and 5 wt% HKUST-1/IL-CS membranes, as high as 5413 191 Barrer and 11.5, and 4754 1388 Barrer and 19.3, respectively. This is attributed to a better adhesion and smaller particle size of ZIF-8 than HKUST-1 nanoparticles with respect to the IL-CS continuous matrix, as interpreted by Hansen solubility parameters and Maxwell-based models, modified to account for rigidification, pore blockage and crystallinity of the CS matrix, with very accurate predictions. ; Financial support from the Spanish Ministry of Economy and Competitiveness (MINECO) for the project CTQ2012-31229 at the University of Cantabria, and MAT2013-40556-R, at the University of Zaragoza, is gratefully acknowledged. C.C.C. and A.F.B. also thank the MINECO for the Ramon y Cajal contract (RYC-2011-08550) and the post-graduate research grant (BES2013-064266), respectively, at the Universidad de Cantabria. Dr. Sara Sorribas is gratefully thanked for her technical assistance on the XRD, SEM and TEM analyses. The microscopy work was done at the Laboratorio de Microscopias Avanzadas of the Instituto de Nanociencia de Aragon (LMA-INA), and the XRD measurements were carried out at the Servicio General de Apoyo a la Investigacion (SAI) of the Universidad de Zaragoza.