The zebrafish, Danio rerio, has become a popular model organism in basic biology and biomedicine. It is easy to breed in the laboratory and provides researchers with large amounts of synchronously developing embryos, making it an organism of choice for genetics and developmental biology. Embryos and larvae are largely transparent, allowing to assess organ development noninvasively. Embryos can be genetically engineered to express proteins that permit to fluorescently label distinct tissues or cell types, allow to measure neural activity, or enable visualization of hormonal signaling in the living organism. These experimental features have stimulated the use of zebrafish for research in many areas of biology, such as neurobiology, drug development, and toxicology. In this Café Scientifique presentation, Thomas Dickmeis from the Karlsruher Institute for Technology (KIT), will review some of the recent developments in the use of zebrafish embryos for the assessment of chemical compound effects on different organs and physiological processes, including developmental toxicity, cardiovascular toxicity, endocrine disruption, and neurotoxicity. A particular focus will be placed on methods for the automatization of chemical screening procedures and the sophisticated imaging possibilities available in this model system.