Spices, active ingredients of Indian cooking, may play important roles in prevention and treatment of various cancers. The objective of the present study is to compare the in vitro anticancer activities of three different extracts of Clove (Syzygium aromaticum L), a commonly used spice and food flavouring agent, against different kinds of cancer cell lines of various anatomical derivations. Water, ethanol and oil extracts were screened for anti proliferative activity against HeLa (cervical cancer), MCF-7 (ER + ve) and MDA-MB-231 (ER - ve) breast cancer, DU-145 prostate cancer and TE-13 esophageal cancer cell lines, along with normal human peripheral blood lymphocytes. Inhibition of cell proliferation was assessed using MTT assay as a vital stain. In the examined five cancer cell lines, the extracts showed different patterns of cell growth inhibition activity, with the oil extract having maximal cytotoxic activity. Morphological analysis and DAPI staining showed cytotoxicity to be a result of cell disruption with subsequent membrane rupture. Maximum cell death and apoptotic cell demise occurred in TE-13 cells within 24 hours by clove oil at 300 μl/ml with 80% cell death whereas DU-145 cells showed minimal cell death. At the same time, no significant cytotoxicity was found in human PBMC's at the same dose.