In her book Silent Spring, Rachel Carson describes the cata strophic effects of the indiscriminate use of pesticides in the 1940s and 1950s. These substances, most of them insecticides, have since been designated as persistent organic pollutants and are regulated nationally and internationally. They have sub sequently been replaced by less persistent yet highly toxic compounds. The experience gained in those decades triggered environmental regulation and risk assessment schemes. The ecotoxicological tests required for risk assessment greatly advanced the development of new concepts and tools in this field. Today, we are no longer faced with disastrous poisonings such as those described in Silent Spring. Nevertheless, the same compounds are still present in the environment adding to the increasing number of chemicals organisms must cope with.Many ecotoxicological questions remain to be solved and new ones have emerged regarding, eg., the effects of nanomaterials, the phenomenon of bee colony collapse disorder, and the consequences of climate change.