To generate temporally controlled site-specific somatic mutations in the mouse eye pigment epithelium, we generated a TRP1-Cre-ERT2 transgenic mouse line that expresses the tamoxifen-dependent Cre-ERT2 recombinase under the control of the tyrosinase-related protein 1 (TRP1) promoter. Cre-ERT2 transcripts were readily detected in the retinal pigment epithelium (RPE), and tamoxifen treatment of adult TRP1-Cre-ERT2 transgenic mice induced efficient excision of floxed DNA in patches of RPE cells, in numerous epithelial cells of the iris and ciliary body, and in very few cells of the neural retina. Importantly, no excision was detected in any cells in the absence of tamoxifen treatment. Thus, the TRP1-Cre-ERT2 mouse line provides a powerful tool to study in vivo gene functions in the mouse eye pigment epithelium. genesis 1–18 2012. © 2012 Wiley Periodicals, Inc.