Research into venoms have been extensively developed during the last years, and some groups of venomous animals seldom studied have been recently the subject of new important results, such as the Cones (Gasteropodes, Molluscs) and Spiders, in the venom of which new types of neurotoxic molecules have been described. Concerning the most studied groups, new toxic molecules have been identified in snake (Dendroaspis sp., Atractaspis sp.) and scorpion venoms. The scorpion venoms contain a large variety of toxins acting on various ionic channels, Na+, K+, Ca++ or Cl-. Many structural relations between venomous toxins (Cones and Najas) or between toxins and physiological molecules (sarafotoxins and endothelins, scorpion toxins and Arthropod defensins) have been described and raise important phylogenetic problems which might be also the starting point of new domains of applied research.