Syngeneic and transgenic mouse models are important tools for the study of the biology of cancer. While syngeneic mouse models are generated through the implantation in host animals of tumor cells from genetically and immunologically compatible donors, transgenic mouse models are engineered to express genetic material with oncogenic properties in predetermined location. We have developed a syngeneic mouse model of ovarian cancer permitting in vivo imaging in immunocompetent recipients by implanting ovaries with fluorescently labeled cancer cells that derived from a spontaneous ovarian tumor developing in a transgenic mouse model. Tumor cells were retrovirally transduced with a far-red fluorescent protein. This animal model combines the advantages of syngeneic and transgenic mouse models as it permits to both monitor tumor growth by in vivo imaging and to analyze the tumor microenvironment of an immunocompetent host.