To assess the possibility of substituting our routine method (dextran-coated charcoal, DCC) of determining estrogen (ER) and progesterone receptors (PR) for an enzyme immunoassay technique (EIA), we compared the two methods for determination of the two types of receptor in breast cancer specimens. In terms of sample positivity or negativity, the two techniques agreed in 76 of the 82 samples analyzed for ER (92.7%; p < 0.001), and in 65 out of 75 samples assayed for PR (86.6%; p < 0.001). Quantitative analysis of the data showed a significant correlation between DCC and EIA for both ER (r = 0.84; p < 0.0001) and PR (r = 0.77; p < 0.0001). The results suggest the usefulness of EIA in substituting DCC, although further clinical studies are required to fully evaluate this new method.