Multiaxial experiments are performed on replicated aluminium foam using a custom-built apparatus. The foam structure is isotropic, and features open monomodal pores 75 mu m in average diameter. Plane stress (sigma(1), sigma(2), sigma(3) = 0) and axisymmetric (sigma(1), sigma(2) = sigma(3)) yield envelopes are measured using cubical specimens, supplemented by tests on hollow cylindrical and uniaxial samples. In addition to the three stress components at 0.2% offset strain, the computer-controlled testing apparatus also measures the three instantaneous displacement vectors.