In the next generation of magnetic fusion experiments, such as ITER, information on ion temperature profiles will be needed for bum optimisation and transport studies. The feasibility of obtaining these profiles for the core plasma (r<0.75a) directly from the width of measured 14MeV neutron energy spectra is demonstrated for Maxwellian ion distributions. Neutron energy spectra and fluxes are calculated using the Monte-Carlo technique. Reaction kinemat­ics and velocity distribution of the reacting ions are taken into account enabling resulting neutron flux and energy distribution, entering a defined collimator, to be calculated. Energy spectra of neutrons emitted along a line-of-sight are obtained by adding the contributions from a large number of sub-volumes. The associated correction factor (peak temperature/line­-of-sight measured temperature) depends on the ion temperature itself and is insensitive to variations in temperature-, density- and magnetic flux profiles. The resulting accuracy in the evaluated ion temperature profiles is expected to be better than ±10%. However, this can be improved to± 5% provided the ion density profile shape is known. The relative accuracy is estimated to ±5%. Features of several spectrometer candidates are briefly described in relation to ITER conditions and measurement requirements. A Time-of-Flight neutron spectrometer is outlined. Experiments with a test device confirm the calculated energy resolution and separation of neutron from gamma events. The spectrometer is shown to be applicable to ITER under both ohmically heated and ignited conditions. A feed-back system will be used to control the de­tector count-rate at high neutron flux levels to accommodate the large dynamic neutron flux range from 5.106 to 5.10101 n/(cm2s). An array of 5-9 Time-of-Flight spectrometers provides ion temperature profiles satisfying ITER measurement requirements, i.e. Ti ≥ 2.5keV, 10% accuracy and spatial and temporal resolutions of 30cm and 100ms respectively.