Residue measurements for persistent organochlorine pesticides in milk, butter, corned beef, beef fat and mutton fat, produced in or imported into Britain in 1963 and 1964 are reported. The levels in mutton fat are compared with levels found earlier; only very low residues are found in most other produce examined though some butter samples contain up to 0·1 ppm of DDT and 0·4 ppm of total DDT equivalent. Levels in the fat of grass and store‐fed animals were indistinguishable; results for milk suggest that the diet of cows in Britain contains very little γ‐BHC or dieldrin.