The vapour pressure of two metal organic precursors, Y(thd)(3) [CAS RN: 15632-39-0] and Zr(thd)(4) [CAS RN: 18865-74-2] (thd = 2,2,6,6-tetramethylheptane-3,5-dionate), used for metal organic chemical vapour deposition of high-temperature superconductor layers, was measured by a static method in the technologically important temperature range from 395 to 465 K. The experimental data were fitted by simple two-parameter equation and represent updated values of the present day high-purity materials providing comparison with the previously published data. Heat capacities in the temperature range from 308 to 565 K are also reported. (C) 2004 Elsevier B.V. All rights reserved.