This short review has shown the existence of several serious uncertainties on actual possibilities of long-distance laser communication systems. We must however point out that lasers only appeared a few years ago and that notwithstanding the great effort going on in many laboratories, many aspects of the problems concerning the application of laser to communication have not been adequately examined yet. The possibility and the extent of laser application to communication depend on the outcome of research in many fields, some of which, as those concerning modulation and detection, are not, strictly speaking, limited to lasers. There are such enthusiasm and vigour of research in the laser field that it is likely that, in a near future, it will be possible to have a better knowledge of the actual possibilities of laser application to communication in traditional schemes or in new ones which may develop using particular properties of laser beams.