Phytochemical Analysis and Plant Mediated Nanoparticles Synthesis from Quercus Incana Traditional medicines play significant role as healers, in addition to the synthetic drugs, for different diseases. Plants form a significant part of traditional healing and hence, Quercus incana was chosen for nanoparticles synthesis, biological screening and phytochemical analysis to determine a scientific basis for the traditional use of this plant. The phytochemical screening was carried out using column chromatography (CC) followed by thin layer chromatography (TLC), identification and structure elucidation of pure compounds were done by using spectroscopic and spectrometric techniques (1D and 2D-NMR, IR, UV, Mass). Through phytochemical analysis, fourteen compounds were isolated, among them four compounds (decane-1, 1,4-triol [1], 4-hydroxy-3-(hydroxymethyl) pentanoic acid [2], 2-(4-hydroxybutan-2-yl)-5-methoxyphenol [3], and 3-(2-hydroxy-4 methoxyphenyl) butane-1, 1-diol) [4] were new rare class of aliphatic alcohols and acids. Along these new compounds ten known compounds (Cirsimaritian [5], Eupatorin [6], b-amyrin [7], Betulin [8], Ursolic Acid [9], 3 β-hydroxy-30-Norlupan-20-one[10], 12-Oleanen-3yl acetate [11], β-Sitosteryl-D-glycoside [12], 1-Triacontanol [13], and 4-methoxy-1-methyl-2-oxo-1, 2-dihydropyridine-3-carbonitrile) [14], were isolated for the first time from Quercus incana except Ursolic Acid. Small sized, polydispersed gold nanoparticles were synthesized using all fractions of Quercus incana (n-hexane, chloroform, ethyl acetate, n-butanol, aqueous fraction) and isolated compound (b-amyrin). 4-Methoxy-1-methyl-2-oxo-1, 2-dihydropyridine-3-carbonitrile was used for the synthesis of monodispersed silver nanoparticles. Biological screening of extracts, nanoparticles and pure compounds showed tremendous results. All fractions of Quercus incana were analyzed for antioxidant activity, nitric oxide scavenging activity, total phenolic content and antimicrobial potential. Among all fractions, ethyl acetate and n-butanol fractions showed immense biological activities as these fractions may contain polyhydroxy compounds which contribute to the enhancement of activities. Synthesized nanoparticles were screened for antibacterial activity and it was found that extract xi loaded nanoparticles may be used as antibacterial agents by comparing it with crude extract. Crude extract was found inactive at low concentration whereas nanoparticles showed good activity against human pathogens. The unique properties of silver and gold nanoparticles have stimulated the increasing interest in the application of nanoparticles in interfacing biological recognition events with signal transduction and in designing biosensing devices exhibiting novel functions. The recognition behavior of nanoparticles were explored with different drugs and results showed that only Ag-NPs (4-methoxy-1-methyl-2-oxo-1, 2-dihydropyridine-3-carbonitrile) had biosensing ability towards cephalexin. Isolated compounds were screened for anti-biofilm, cytotoxic and anticancer activity. Eupatorin, Cirsimaritin and β-Sitosteryl-D-glycoside showed good anti-biofilm activity which explored the medicinal use of these compounds in pharmaceutics as an anti-biofilm agent. A preliminary screening of natural product compounds was carried out against NCI-H460 (Non-Small Cell Lung Carcinoma) cell line. The compounds; 12-Oleanen-3yl acetate, Betulin, Eupatorin, and Cirsimaritin showed good anticancer activity. The compound, 12-Oleanen-3yl acetate was found more active anticancer agent against NCI-H460 cell line. Similarly, Cirsimaritin, 12-Oleanen-3yl acetate and Betulin showed good cytotoxic activity against NIH-3t3 (Normal Fibroblast) cell line.