DsRed-monomer is an enhanced red fluorescent protein that may serve as a marker for studies in biotechnology and cell biology. Since the ICR mouse strain is a widely utilized outbred strain for oncology, toxicology, vaccine development and for aging studies, the objective of this study was to produce a DsRed-monomer transgenic mouse by means of pronuclear micro-injection of a vector driven by the cytomegalovirus (CMV) enhancer/chicken beta-actin promoter. Four transgenic mice were successfully produced, one of which expressed the DsRed-monomer protein in every tissue, although at varying levels. High expression levels were observed in the heart, pancreas and muscle. Moreover, amniotic fluid-derived progenitor cells, which also expressed the DsRed-monomer protein, could be collected from the DsRed-monomer- harboring ICR mice. As compared to wild-type mice, a few biochemical and histological dissimilarities were found in the DsRed-monomer transgenic mice, including the presence of intra-cytoplasmic eosinophilic threadlike materials in the acinar cells. Taken together, transgenic mice stably expressing DsRed-monomer can be produced using pronuclear micro-injection; however, expression of the DsRed-monomer gene or its insertion position may lead to minor influences.