Silver nanoparticles show enhanced properties, when supported onto a substrate and incorporated into organic or inorganic matrix. Their remarkable properties are shape and size dependent. Ethylene glycol and its polymers are environment friendly or environmentally benign materials as compared to the other reducing agents like hydrazine, dimethyl formamide, sodium borohydride etc. used in the preparation of nanoparticles. In this paper the role of poly ethylene glycol (PEG) as a reducing as well as stabilizing agent has been studied. The reducing reactivity of PEG is sensitive to its molecular weight, thus a study has been made on establishing the optimum length of PEG that exhibits maximum reducing abilities. Apart from the molecular weight, viscosity is another parameter that will control the size of the nanoparticles. Thus, different molecular weight PEG, ranging from 200 to 8000 have been tried to analyses the effect of chain length of the PEG on nanoparticle synthesis of size controlled silver nanoparticles. The use of biocompatible reagents, such as PEG, provides green and economic features to this work.