In this paper, we report on biosynthesis of silver nanoparticles using Gracilaria corticata (Red seaweed) at room temperature along with photo-catalytic degradation of Malachite green dye. UV spectral analysis showed peak at 380 nm with special reference to the excitation of surfaces plasmon vibration by silver nanoparticles. The morphology of silver nanoparticles was found to be spherical and ranges about 100 nm as confirmed by HR-SEM. Positive zeta potential value of suggests that the nanoparticles are moderately stable in colloidal solution. Further, photo-catalytic degradation of malachite was measured spectrophotometrically by using silver as nano-catalyst under visible light illumination. The results revealed that biosynthesized silver nanoparticles using Gracilaria corticata was found to be impressive in degrading malachite green. | Degradation of malachite green Dye by using photo-catalytic biogenic silver nanoparticles synthesized using red algae Gracilaria corticata aqueous extract