The design, construction and testing of two large reinforced concrete beam-column assemblies, representing an interior and an exterior joint, are described. Member details were based on an actual frame building designed by the M.W.D. Extensive results are presented which indicate very satisfactory behaviour particularly in the joint region. Hinges formed in the beams in all cases, and stable behaviour was obtained at displacement ductility factors of up to 6 and 8 for the interior and exterior test units respectively. Results are assessed in terms of design assumptions, and tentative design recommendations are made.