A finite element implementation of the Hill anisotropic model has been applied to the problem of the determination of the steady-state creep behaviour of an internally-pressurised, two-material, axisymmetric P91 welded pipe. The anisotropic model results have been validated against an available analytical solution using homogeneous steady-state creep properties. In the two-material model, the parent (base) metal is assumed to be isotropic while the weld metal is assigned different creep properties in the welding direction (circumferential) and the direction transverse to welding, consistent with observations on the creep behaviour of P91 weld metal. The anisotropic material behaviour of the pipe was characterised using two constants, p and S, which respectively represent (a) the ratio of transverse to longitudinal creep strain rates in the weld metal and (b) the ratio of weld metal longitudinal to parent metal creep strain rates. The effects of these parameters on the stresses at critical positions were studied parametrically, along with the Norton stress exponent, n, and different end loading conditions.