In this work,preparationand characterization of Silver nanoparticles which were synthesized by pulsed (Q-switched, 1064 and 532nm doubled frequency-Nd: YAG) laser ablation of silver metal immersed in double distilled and deionized water DDDW, without any chemical additives and studied the optical, and antibacterial properties by using different techniques. The fluence of laser parameters such as number of pulses as well as laser fluence on the properties of nanoparticles elucidated. It has been observed that laser energy and number of laser pulses have a control over the size of the nanoparticles. Increasing laser energy and number of pulses shows a clear blue shift in the absorption peak of fabricated nanoparticles indicating that the average size of the particles decreases with increasing laser energy and number of pulses. Ablation for longer period reduces the average size of nanoparticles.The Antibacterial of synthesized silver NPs against four pathogens: streptococcus, staphylococcus, proteus and Enterobacterwere studied.