This retrospective study of recurrent basal cell carcinoma suggests the presence of irregularity in the peripheral palisade (IPP), squamous differentiation (SD), and tumor ulceration as histologic criteria for the recurrent tumor and the presence of infiltrates of small lymphocytes (LI) in the tumor as a criterion of tumor-directed host immunocompetence. The presence of either irregularity in the peripheral palisade in greater than 75 percent of the tumor cords or absence of infiltrates of small lymphocytes at the tumor base were each significant at the p less than 0.001 level in characterizing recurrent basal cell carcinoma.