Special nanoporous fillers for enhancing the gas separation performance of mixed matrix membranes (MMMs) are addressed in this work. The incorporation of small amounts of ordered mesoporous silica spheres (MSS) or exfoliated layered microporous titanosilicate UZAR-S1 (obtained from layered material JDF-L1) into a commercial polysulfone (PSF) membrane matrix was successfully carried out. The obtained results in terms of the separation of H 2/CH 4 and CO 2/N 2 mixtures were compared to those achieved with special fillers in the literature, such as mesoporous molecular sieves, lamellar zeolites and metal-organic frameworks. 8 wt.% MSS- PSF MMMs gave rise to H 2/CH 4 and CO 2/N 2 selectivities of 79.2 and 36.0 with H 2 and CO 2 permeabilities of 26.5 and 12.6 Barrer, respectively. 4 wt.% UZAR-S1-PSF MMM gave rise to H 2/CH 4 selectivity of 69.2 with H 2 permeability of 11.5 Barrer.