Throughout the ages, humans have relied on nature for their basic needs in terms of shelter, clothing, food, flavors and fragrances as not the least, medicines. In accordance with the recent interest in plant derived drugs and when taking into consideration that many of these drugs might be of phenolic, terpenoidal or alkaloidal nature, it becomes therefore a necessity to subject extracts of some promising medicinal plants to accurate and comprehensive bioassay guided chemical investigations. As a result of this intensive study, eleven phenolic compounds were individually isolated and identified from the methanolic extract of Clove (Syzygium Aromaticum) flower buds, while, ten volatile constituents were identified by GC-MS from the volatile oil. The structure of these compounds was supported by their spectrum, elemental analysis and chromatographic analysis as HPLC, GC/MS and PC. On the other hand, the methanolic extract and volatile oil have been subjected to certain (in vitro) biological studies including the evaluation of the antioxidant activity against the stable free radical DPPH, cytotoxic activity on liver, colon and breast and its activities as antimicrobial.