1. Improvements are described in the methods for the extraction and colorimetric estimation of metals in dairy produce, using the carbamate reagent for copper and thiocyanate for iron.2. A combined filtration procedure has been developed to enable both metals to be determined on the same sample, and with slight modifications this procedure has been applied to the analysis of samples of butter, cream, buttermilk and whey.3. The wet-ashing technique has also been improved to enable it to be used for the estimation of both metals on the same digest.4. Comparisons show that the combined filtration method is capable of giving results which agree very well with those yielded by wet-ashing.5. The results of many analyses show that the majority of creamery butter samples have a satisfactorily low content of both copper and iron.6. Many whey butter samples have a rather high metallic content.7. Notes are given on the results obtained when the methods described are applied to other dairy produce.