In this study the isomerisation of some 2,4-dihaIogeno benzenediazonium compounds was investigated and the isomerisation products were obtained. The halogenoanilines containing chlorine, bromine and iodine in their 2- and 4- positions were used as substrates. The diazctisa- tion reactions were carried out in concentrated sulphuric acid. The nucleophiles used in Sandmeyer reaction were chloride, bromide and iodide. During the isomerisation reactions the chlorine and bromine in 4- position were found to give 1—2 and 1—3 shifts respectively. The structures of the products obtained were elucidate with their physical constants and with spectroscopic methods.