Metal nanoclusters exhibiting enhanced properties are inherently unstable​ ​because of their high specific surface area. This work investigates how the​ ​undesirable agglomeration of these nanostructures can be circumvented by​ ​incorporating them into a polymer matrix. Using aerosol spray pyrolysis (ASP), Ag​ ​and Ni nanoclusters less than 20 nm in diameter have been synthesized by growing​ ​and trapping them within polyvinylpyrrolidone (PVP), polyethylene glycol (PEG),​ ​and polyethylene oxide (PEO). Experimental process variables including the polymer​ ​system’s molecular weight, the temperature of the tube furnace reactor, the carrier gas​ ​flow rate, and the metal salt concentration within the ASP precursor solution have​ ​been studied to understand which parameters govern nanocluster formation and​ ​growth. Having analyzed the correlations that exist between these parameters and the​ ​size distribution of the Ag and Ni nanoclusters, a qualitative model is proposed that​ ​identifies which primary mechanisms underlie the formation of metal nanoclusters​ ​within a polymer matrix.