Summary Kidney cells have been typed for HL‐A antigens using a technique of complement dependent destruction of monolayers of renal epithelial cells in tissue culture by cytotoxic antisera. The degree of concordance between the phenotypes of peripheral blood lymphocytes and kidney cells from the same individual was 80·5%. However, significant discrepancies between the typing of lymphocytes and kidney cells were found for the antigens HL‐A7, 12, 13. Although the majority of the discordant reactions were found with antisera containing more than one antibody, it is felt that the above discrepancies are valid. Positive cross matches between recipient sera and donor kidney cells, together with a negative lymphocytotoxic cross match, were found in four of five cases where the kidney was acutely rejected within three months of transplantation. It is suggested that HL‐A antigens are expressed on both lymphocytes and kidney cells, but either there may be a quantitative difference in their expression on the two cell types, or the monolayer destruction technique may be more sensitive than the lymphocytotoxic technique.