The threshold photo-neutron technique explores the process of resonant absorption of gamma-rays and the decay of the compound state by neutron emission. The authors examine, on the basis of currently obtainable experimental conditions, the class of nuclei and the characteristics which can be investigated to advantage by this technique. With reference to the Bologna facility, some improvements are discussed concerning the measurement of angular distributions, the efficiency and time properties of neutron detectors and the development of computer codes for data analysis.