The synthesis, characterization and application of biologically synthesized nanomaterials are an important aspect in nanotechnology. Biological synthesis of silver nanoparticles has received a tremendous attention and has been a focus of research due to their high chemical, thermal stability and promising applications in medicinal field due to its environmental friendly approach and also low cost techniques. In the present study silver nanoparticles were synthesized using the aqueous extract of red seaweed Gracilaria dura (Ag.) J.Ag. as the reducing agent. The formation of silver nanoparticles was confirmed by colour change, UV-Visible Spectroscopy, FT-IR and X-Ray Diffraction Method (XRD). The nanoparticles showed an absorbance at 446nm on UV-Vis spectroscopy. The presence of proteins was identified by Fourier Transform-Infra Red spectroscopy (FT-IR).The presence of elemental silver was characterized by X-Ray Diffraction Method (XRD).These results not only provide a green approach for the synthesis of nanoparticles but also open a door for new pharmaceutical leads.