Apoptosis triggered by exogenous and endogenous stimuli such as ultraviolet radiation, oxidative stress, and genotoxic chemicals is a crucial phenomenon within biological systems. DNA damage activates and stabilizes p53 in nucleus and cytoplasm and regulates other proteins that stimulate intrinsic and extrinsic apoptotic pathways. Apoptosis is morphologically distinct from that of necrosis and both the phenomena depend on the types, developmental stages, physiological environment of tissues and the nature of death signal. Malfunctioning of apoptotic pathway may cause human diseases like cancer, neurodegenerative and autoimmune disorders. Recently, potent apoptosis-inducing compounds associated with human health have been recorded that prevent tumor promotion, progression, and the occurrence of cellular inflammatory responses. Certain photosensitizing drugs are being employed in photodynamic therapy to induce apoptosis for the treatment of cancer and non-cancerous cells. This review emphasizes the molecular mechanisms of apoptosis, associated diseases and certain therapeutic agents implicated in the elimination of malignant cells.