An intercomparison of measurements on three Er-doped fibres has been organised in the working group 3 of the European COST 217 project (optical measurement techniques for advanced optical fibre systems and devices). A set of fibre parameters, including core diameter, refractive index difference, mode field diameter, cut-off, absorption, fluorescence peak wavelength, time constant, doping concentration and gain, have been measured using samples from three fibres made by three participating laboratories. The measurement results and the properties of the three fibres with different core compositions are compared.