The assessment of the response of reinforced concrete frames to earthquakes is essential in many parts of the world. Therefore, the design and assessment of the structures that are likely to be subjected to such actions require the applications of non-linear analysis using finite element techniques of different degrees of complexity. This state of the art report examines the behaviour of individual frame members subjected to the cyclic actions arising in seismically loaded frames, i. e. slender flexure-dominated beams, slender columns under uniaxial or biaxial bending, deep beams, short columns and beam-column joints. The report also considers global inelastic frame behaviour and it s modelling, and the peculiarities of the behaviour of masonry-filled frames.