In the present work synthesis of novel silver nanocomposite Sg-cl-polyAAm-IA-Ag-0 based on gum Salai guggal semi interpenetrating network (semi-IPN) Sg-cl-polyAAm-IA and its antimicrobial behavior has been described. Semi interpenetrating network was prepared under hot air conditions using acrylamide and N,N'-methylene-bisacrylamide under the initiation impact of ammonium persulphate. Different process variables were optimized and maximum swelling percentage obtained was 667 +/- 11%. The silver nanocomposite was in-situ synthesized through the reduction of silver nitrate using semi-IPN matrix under high energy gamma radiations. The nano-composite prepared was characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), ultraviolet-visible spectroscopy (UV-Vis), fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis/differential thermal analysis/difference thermo gravimetry (TGA/DTA/DTG), X-ray powder diffraction (XRD) and transmission electron microscopic (TEM) technique. Nanocomposite was evaluated against Pseudomonas aeruginosa, Bacillus aureus, Staphylococcus aureus and Escherichia colt for antibacterial activity. Silver nanocomposite possessed potential activity against different gram positive and gram negative bacteria and thus can be used as a precursor for biomedical applications.