Palladium-catalyzed Heck coupling reactions of styrene with bromoarene derivatives are carried out under aerobic conditions in water using water-soluble N,N,N,N'-tetrakis(2-hydroxyethyl)ethylenediamine (EdteH(4)) and ethylenediaminetetraacetic acid disodium salt (Na(2)EDTA) as ligands. The effect of different bases, catalyst loading, and additives is also monitored. The ole fination of bromoarenes with styrene affords the desired products in high yields. The Na2PdCl4 - Na(2)EDTA precatalyst system is also used for the preparative scale (50.0 mmol) synthesis of 4-acetyl-trans-stilbene and 4-styrylbenzaldehyde without a noticeable decrease in the activity. Recycling studies on the Na2PdCl (4) - Na(2)EDTA precatalyst system are also tested in the coupling of 4-bromoacetophenone with styrene.