The photoinitiated polymerization of methyl methacrylate (MMA) using 2,3-diphenylbutadiene (DPB) as cross-linking agent and benzoin (BN), benzoin methyl ether (BME), and irgacure (IGC) as photoinitiators in the presence of poly(N-isopropylacrylamide) (PNIPAM) as a water-soluble, hydrophobic template polymer in H2O/DMF led to the formation of P(MMA/DPB) polymer latex particles. These particles were analyzed by using TEM in combination with the program IMAGE (NIH/USA). After purification by precipitation using THF/H2O, globular latex particles were found. Using BME as photoinitiator, "real nanoparticles" possessing a smaller diameter than 10 nm were formed among bigger particles (d > 20 nm). The CHN analysis of the P(MMA/DPB) polymers indicated that a smaller fraction of PNIPAM (4-10%) was incorporated into the latex particles.