Rhesus monkeys [Macaca mulatta, 120] were typed for RhL-A [rhesus histocompatibility] antigens and 20 animals were paired that shared compatibilities for 2, 3 or 4 antigens. Each monkey received 1 orthotopic tooth allograft and the recipient''s CML [cell-mediated lymphocytotoxicity] response was assayed from the 5th-23rd postoperative day. Single tooth allografts stimulated CML in 17 of 20 matched recipients and could be detected as early as the 5th day. Although 3 tooth recipients proved to be anergic under these conditions, MLR [mixed lymphocyte reaction] assays and the histological evaluation of the transplants must be completed before more definitive statements can be made regarding the influence of histocompatibility typing on tooth transplantation in nonhuman primates.