This study considers the effect of the non-linear behaviour of connections and geometric non-linearity on the behaviour of space frames. The Richard model (Comput, Struct. 1993; 46:55) has been used for the non-linear moment-rotation relation of the connections and the behaviour of the material is assumed to be linearly elastic. The tangent stiffness matrix has been obtained from the solution of the pertinent linear differential equation that governs the moment-curvantre relation of a prismatic member, including the above-mentioned non-linear effects. The non-linear equilibrium equations that show up are solved iteratively using an incremental loading procedure. The iterative procedure is repeated until the unbalanced forces are less than a predefined tolerance. Consequently, the errors emerging due to the linearization of the non-linear analysis can be made as small as desired. An example problem is solved using the computer program written to implement the proposed analysis and the results are in good agreement with those in the literature. Copyright (C) 2002 John Wiley Sons, Ltd.