Transfer to gold fish of brominated hydrocarbons (1-2-dibromoethane, bromoform, 1-1-2-2-tetrabromoethane) from rearing water was examined. The concentration of brominated hydrocarbons in fish flesh reached the first steady state 5 hours after fish were placed in rearing water. The concentration factors (cont. in gold fish/cont. in rearing water at steady state) of brominated hydrocarbons for gold fish were in the decreasing order of: bromoform 1-1-2-2-tetrabromoethane 1-2-dibromoethane.