Poisons and the toxins found in venomous and poisonous organisms have been the focus of much research over the past 70 years, most of which has been directed at understanding the biochemical and physiological mechanisms by which they elicit their dramatic pathological consequences. Much knowledge has been gained in terms of how poisons and venoms and their composite toxins give rise to the syndromes associated with envenoming and poisoning and in some isolated cases there have been a few such agents promoted for therapeutic use. However, it has only been in the past decade that an explosion of interest has occurred in mining these natural, highly evolved libraries of bioactive toxins and poisons for use in pharmacotherapeutics as drugs or drug leads as well as in diagnostic applications. We ascribe this recent phenomenon to advances in toxinology which have provided investigators with a relatively thorough understanding of the nature of venoms and their biologically active toxins: particularly with regard to the peptidomes and proteomes of venoms. This is in conjunction with our greatly improved understanding of the etiology of many human diseases and the identification of sites of potential therapeutic intervention. In this review we provide an overview of some of the toxins, toxin derivatives or poisons from animal venoms and secretions which are in various stages of development for use as pharmaceuticals or diagnostics in human diseases. As one will recognize, developments in this field suggest that toxinology is now entering a golden age in terms of the identification and use of toxins as potent novel pharmaceuticals.