Engineering the self-assembly of inorganic nanoparticles within block copolymer nanodomains is very useful for the design of periodic structures to form materials with enhanced mechanical strength as well as to achieve unique optical, electronic and magnetic properties on the nanometer scale. In this work three types of nanocomposites based on different block copolymers and nanoparticles modified with polymeric brushes by different methods are prepared and characterized. First, the selective placement of magnetic Fe3O4 nanoparticles into polymethylmethacrylate (PMMA) domains of poly(2-vinylpiridine-b-methylmethacrylate) (P2VP-b-PMMA) copolymer self-assembled by solvent vapor annealing is achieved by grafting PMMA chains from the nanoparticle surface by ATRP. Due to the increased compatibility among the nanoparticles and one of the blocks of the block copolymer, magnetic nanoparticles are placed at PMMA domains. Magnetic properties of obtained nanocomposites are analyzed. Secondly, self-synthetized CdSe quantum dots are modified in their surface with poly(styrene) (PS) chains by grafting through technique in order to selectively place them into PS domains of poly(styrene-b-butadiene-b-styrene) (SBS) block copolymer nanostructured by thermal annealing. Optical and electrical properties of nanocomposites are measured showing that nanoparticle properties have been transferred to the nanocomposite film. Finally, magnetic Fe2O3 nanoparticles are modified in their surface by grafting chlorine-ended poly(methylmethacrylate-b-caprolactone) (PMMA-b-PCL) copolymer to their surface by grafting to method. Then nanoparticles are selectively dispersed into self-assembled PS-b-PCL copolymer films in order to confer them magnetic properties. A comparison among different techniques to modify nanoparticle surface is done showing main differences among them, especially on obtained morphologies and properties. Second, CdSe quantum dots