The status of fast reactor dosimetry is reviewed in terms of the results of recent studies in fast test reactors. Fast reactor dosimetry must provide proper spectral, flux, and fluence information for material and fuel irradiation effects programs and surveillance studies. In this review consideration is given to (1) monitor materials in current use and information needed in the data reduction of reaction product measurements to neutron interaction rates, (2) neutron flux-spectral definition from multiple foil interaction rates and comparison with results based on other methods of analysis, and (3) application of the flux-spectral data to determination of flux levels and fluences. These dosimetry techniques are applied to determine flux spectra and fluence for material irradiation programs. Such information is needed in the determination of damage functions, which relate the damage producing effectiveness of neutrons to their energy. These damage functions permit correlation of irradiation effects data in different thermal and fast reactor irradiation facilities and therefore provide a basis for setting dosimetry accuracy requirements.