This review focuses on recent update in the understanding of programmed cell death regarding the differences and similarities between the diverse types of cell death in animal and plant systems and describes the morphological and some biochemical determinants. The role of PCD in plant development and stress response, the involvement of plant proteases with similarities to animal caspases and the role of oxidative stress and ethylene have been discussed as key players in plant suicidal machinery. Our contribution to chemical and pathogen-induced cell death in tomato cell culture in response to camptotecin and cadmium and in response to P. syringae pv. tabaci respectively has been described and discussed. Hypersensitive response has been reviewed as a form of plant PCD representing the defence against diseases and some of the major biochemical features of HR have been discussed. The importance of studies on HR in terms of manipulation the disease resistance in plants has been outlined. Studies on plant PCD have been demonstrated to provide a clue to better understanding the process in plants and to establish the evolutionary aspects of PCD similarities through animal and plant kingdoms.