Diphenylzinc-water systems, Ph(2)Zn-H2O, were aged at various temperatures and for various lengths of time. These systems by themselves and those to which t-butyl chloride was added, ph(2)Zn-H2O-Bu(t)Cl, were used as initiator for styrene polymerizations. For Ph(2)Zn-H2O systems, both conversion and molecular weight of the polymers were much affected by ageing. Ph(2)Zn-H2O-Bu(t)Cl systems, after ageing at various temperatures, did not improve their capability to induce styrene polymerization at -78 degrees C in dichloromethane, confirming their ionic nature.