Taking advantage of a mutant estrogen receptor ligand binding domain (ER(T2)), we developed novel Caspase fusion proteins for inducible apoptosis. We show that Caspase-ER(T2) fusion proteins become specifically activated by the synthetic ligand 4-OH- tamoxifen and rapidly induce apoptotic cell death in human, murine, and zebrafish cells. This novel tool for targeted cell ablation greatly facilitates the generation of disease models as well as developmental and regeneration studies in model organisms.