Chlordecone, known under the tradename Kepone, is a highly chlorinated cyclodiene pesticide that is resistant to microbial degradation. Six month chlordecone enrichment cultures yielded several Gram-negative microorganisms that were resistant to and/or degraded chlordecone. Three Pseudomonas spp. were further characterized for their chlordecone degrading ability. Chlordecone and two derivates, Mirex and Kelevan, supported growth of these strains. All three Pseudomonas spp. reduced the concentration of chlordecone in the medium after 14 days incubation as determined by HPLC analysis when it was added either as sole carbon source or in the presence of medium supplements.