Primary renal cell tumors were described in four nonhuman primates (Erythrocebus patas, Macaca cyclopis, Mandrillus sphinx, and Macaca fascicularis) that have been kept for exhibition at Seoul Zoo. Histologically, all of them were renal adenoma. Each one was clear cell type and tubular type, respectively. The rest two were papillary type adenoma. Clear cell type adenoma was bilaterally affected.