The fisrt part of the paper deals with the activities performed in the past at ENEA-SIEC in the field of the thermal-hydraulic design of neutron targets: the IFMIF one (International Fusion Material Irradiation Facility) and the BNCT one (Boron Captured Neutron Teraphy). The codes developed in the frame of such activities, respectively the RIGEL and the ROTA ones, are also presented. In the second part, are proposed and discussed some target architectures, allowing for a heat deposition ranging from 300 KW up to 3 MW. Such solutions are concerned with solid rotating targets (made by beryllium and carbon) only cooled by thermal radiation; with the possibility to cool a solid rotating target by means of helium; with a liquid lithium jet target. Basing on the results of preliminary calculations performed with the codes RIGEL and ROTA, all the proposed targets seems to be feasible. Anyway, and basing only on the thermal-hydraulic features, the liquid lithium jet seems to be the most preferable system.