A Streptomyces, apparently S. viridochromogenes, was isolated from Louisiana crop areas where seven chlorinated herbicides had been used in weed control. It liberated no chloride when grown in a liquid medium containing 100 ppm of any of these seven herbicides. With a cucumber root bioassay, detoxification of 2,4-dichlorophenoxyacetic acid (2,4-D), 2-(2,4,5-trichlorophenoxy)propionic acid (silvex), 2,3,6-trichlorophenylacetic acid (fenac), 2,2-dichloropropionic acid (dalapon) was observed, but little detoxification was shown with 2-chloro-N,N-diallylacetamide (CDAA), isopropyl N-(3-chlorophenyl)carbamate (CIPC), and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T). Manometric studies with 2,4-D, 2,4,5-T, and silvex showed the streptomycete was capable of adapting to the compounds after a short period, but not to 2,4-dichlorophenol, a proposed intermediate of 2,4-D metabolism. The organism did not alter the ring structure of the aromatic herbicides, and 2,4-D and 2,4-dichlorophenol showed identical absorption curves with the spectrophotometer used.