Pathogenic bacteria exert their harmful effects in host through a cascade of virulence factors: exotoxins, endotoxin, invasions proteins and the like. Various toxins secreted by different bacteria not only subvert the host intracellular signaling pathways but also have unique affinity for specific host cells. Detailed information has been accumulated over the years regarding the purification, chemical characterization, enzymic action and architecture of various bacterial toxins. Toxins ability to bind to the specific target cells makes them good candidate for drug delivery and in cancer therapeutics. A number of immunotoxins; hybrid molecules of bacterial toxins and antibodies, have wide applications in cancer and are currently under clinical trial. Advances in genomics and proteomics have created a wealth of information related to the nucleotide and protein sequences of numerous toxins and different databases (DBETH, VFDB, BETAWRAP, RASTA) are available with elaborate information thereof. In present review we have provided a brief account of therapeutic aspect of bacterial toxins and an effort has been made to facilitate the reader’s understanding as to how we can turn the vicious toxin into virtuous toxin for human benefits.