1. A general method was developed for the synthesis of mixed organoarsenic compounds of the type ArAr'AsX. In consists in the action of sodium iodide on a mixture of an aryldichloroarsine and a double diazonium ferric or zinc chloride (ArN2Cl · FeCl3 or (ArN2Cl)2 · ZnCl2) in an acetone medium in the cold. Yields of 40–60% were obtained. 2. A method was developed for the synthesis in 50–80 yield of triarylarsines of the type ArAr'Ar"As. It consists in reaction of mixed diarylchloroarsines ArAr'AsCl with double diazonium zinc or ferric chlorides in the cold in an acetone medium in presence of iron powder.