n this study, two differ~1t antioxidant activity quantification methods: (2,2-diphcnyl-J­ picrylhydrazyl radical scavenging (DPPl-l) and reducing power, FRAP including total phenolic, TPC assays of crudeextract of P. Zeylanica root was performed, The extracts showed significant activities jn all antioxiJ;i1\t assays in a concentration dependent manner. Crude extract was found • • to possess higher ferric reducing activity (ascorbic acid equivalents 227.011 ± 0.047.1113 1\J\!IOO g) and DPPH activity or 156.00±0.010 mg AAl)'IOOg. Strong correlation ofTPC with AE1\Ccwm and Al'.ACfRA~ (R - 0.9745 and R = 0.'!6652 respectively) implied Lhat compounds in the ~xtrnct were capable of scavenging the OPPH free radical and reducing ferric ions. Antimicrobial activities evaluation of crude extract against S.aureus ;\TCC, Ml{SA, S.pneum(H1iae 1\TCC, S. pneumonlae (clinical) (xram positive bacteria}, K. pneumoniae K.ey words: Antioxidant activity. Plumbago zeylanica /111al phenolic con/em. antimicrobial activity, n1i11i11n11rl inhibitory concentration, minimum oactertot .concentration, minimum jungo! concentration and human ptuhogenic bacierta t (clinical), S. boydti ;\TCC, !:'. coli ATCC, E. cau (clinical) (gram neyutive iiacteria; and antifungal activity against C. albicans (clinical) ( fungus] were also exhibited a higher