Cell lines established from the biopsy specimen of a patient with a spindle B choroidal melanoma were transplanted into the posterior choroid of 30 immunosuppressed, pigmented New Zealand rabbits. Growth of the tumor xenografts could be seen 7 to 10 days after transplantation. Tumor xenografts were reproducible and reached an average size of 5 mm in height and 8 mm in their basal dimension by 4 weeks. Histopathology of the original tumor revealed primarily spindle B cells, while the tumor xenografts contained epithelioid, spindle B, and clear cell melanoma cells. Of particular interest was the presence of an extensive and intact vasculature and the absence of a capsule surrounding the lesions in situ. The use of human uveal melanoma cells, the ease of transplantation, and the posterior location of the tumor may make this animal model of use in studies on new diagnostic and therapeutic modalities.