Micromechanical models of 3-3 piezocomposites have previously relied on an ide-alised unit cell containing a single pore. This oversimplification has contributed to the poor agreement between experimental and model results. With increased compu-tational power and more efficient modelling techniques, larger models can be created to represent a network structure with numerous randomly placed pores, filled with a secondary passive phase of air or polymer. Such models more closely represent a porous microstructure and enable the prediction of hydrostatic figures of merit. A series of large three-dimensional porous piezocomposite structures were modelled, with predicted val-ues in good agreement with existing experimental results. In addition, modelling a large number of random porous microstructures revealed the variability in composite prop-erties, as is found in practise.