Offering a broad range of methods, Zebrafish explains how to assess compound-induced toxicity in all major organs using the zebrafish as a model organism. The authors effectively demonstrate why this vertebrate model offers compelling experimental advantages, including drug delivery directly in the fish water, small quantity of drug required per experiment, statistically significant number of animals per test, and low cost. Moreover, the authors describe how drug assessment can be performed using wild-type, mutant, transgenic, and knock-down zebrafish models.