The vapour pressure of four metal organic precursors. diethylzinc. triethylantimony. trimethylgallium and trimethylaluminium. used in the metal organic vapor phase epitaxy processes was measured by a static method in the technologically important temperature range from 238 to 293 K. The experimental data, were fitted by the Antoine equation and represent updated values of the present day high-purity materials providing comparison with the previously published data, (C) 2002 Elsevier Science B.V. All rights reserved.