As part of a research programme dealing with the flexibility behaviour of multiplanar joints in circular hollow sections, the flexibility of various types of multiplanar joints are investigated. This paper deals mainly with the flexibility behaviour of multiplanar XX-joints, with comparisons on the influence of the finite element (FE) modelling and computer costs (disc space and CPU-time). For the whole range of the joint parameters β, γ and τ, the joint flexibility has been investigated with and without inclusion of the weld shape for various load cases, such as axial loading, in-plane bending and out-of-plane bending. The results obtained can be used in determining the local joint flexibility of tubular joints, and calculating the deflection and load distribution of structures containing multiplanar joints. Introduction. Multiplanar joints are frequently used in tubular structures e.g. in offshore jacket structures, triangular or rectangular girders, towers, etc. Local joint flexibility affects the load distribution and deflection of such structures and this work shows some quantitative results. There is little information [2-6] on the flexibility behaviour of tubular multiplanar joints and, to the authors'' knowledge, insufficient information on FE modelling for joint flexibility is available. The results of the numerical investigation (in the linear-elastic range) are presented using different types of FE models for comparison purposes. Several conclusions are established from the results, which should be considered when tubular joints are analysed numerically. Numerical investigation on FE models. For defining the flexibility of a tubular joint the finite element (FE) method is used in the present work. In the past, numerical studies on joint flexibility have been mostly carried out using 4-noded or 8-noded shell elements only (without modelling the weld shape), and models having a coarse mesh.