The advancement of new synthetic ways for the preparation of monodispersed nanocrystals by the use of cheap, non-toxic and environmentally benign materials become a challenge to the research community in science. The present study deals with the biosynthesis of SnO2 nanoparticles making use of the extract of Garcinia Cambogia as reducing and stabilizing agent. This method is simple, efficient, economic, harmless and eco-friendly. The morphological, surface, and structural studies have been conducted by employing X-ray diffraction analysis (XRD), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), Atomic force microscopy (AFM), Brunauer-Emmet-Teller (BET), Fourier -Transform Infrared spectroscopy (FT-IR) and Raman Spectroscopy. The thermal and optical studies have been performed using TG-DTA analysis, UV–Visible diffuse reflectance spectroscopy and Photoluminescence spectroscopy. The photocatalytic activity of NPs is investigated against methylene blue. Agar well diffusion method is used to study the antibacterial action of the SnO2 nanoparticles with Gram-positive S.aureus along with Gram-negative E. coli. The anti-oxidant activity of SnO2 nanoparticles is confirmed using the DPPH assay.