Deliberate poisoning of domestic animals and wildlife with commercial formulations of pesticides has been documented worldwide. We have compiled the analytical results obtained by four Spanish Laboratories of Veterinary Toxicology since 1990. The frequency of poisonings and the intentional use of pesticides were compared between formulations with restricted and unrestricted use, including the toxicity of the commercial formulations as a covariant in the model. The frequency of poisoning was inversely related with the lethal dose of specific formulations, but not with the amounts consumed in agriculture in Spain. The intentional illegal use of some pesticides as poisons was not affected by the commercial restriction of their formulations, but was inversely correlated with their LD(50). The examination of the data permits us to detect three highly toxic compounds (aldicarb, carbofuran, and strychnine), more widely implicated in animal poisonings than other compounds of similar toxicity.