The principle of micro continuous-flow synthesis of polymer microparticles using a co-flow arrangement with integrated in situ photopolymerization was applied for the synthesis of nanoporous acrylate particles and for polymer composite microparticles containing silver and gold/silver metal nanoparticles. The nano porosity is induced by the addition of diethylene glycol (DEG). Nanoporous and composite polymer particles with sizes between about 50 and 500 mu m have been obtained depending on the diameter of the applied glass capillary and the flow conditions during droplet formation. DEG acts as a mediator for miscibility and allows the addition of silver salt and tetrachloroauric acid as well as ascorbic acid for enhancing the reduction of metal ions in the reaction mixture. The formation of metal nanoparticles takes place mainly during the UV-light-induced polymerization. The presence of metal nanoparticles inside the polymer matrix was proved by SEM imaging and EDX analysis.