This study aims to show how UFO scientists have constructed the UFO phenomenon in relation to science, by using discourse analysis. This work expands on the existing literature concerning the social construction of scientific knowledge. Several published papers written by distinguished scientists, supporting the UFO phenomenon, were used as the basis for the analysis. Main themes were identified in the discourse that had been used by the UFO scientists to construct the UFO phenomenon in relation to science. The UFO scientists constructed themselves as scientific experts and in possession of specialist knowledge, especially in relation to their critics. The UFO scientists aligned their work, in particular their methods, with that of other accepted sciences, such as astronomy. Finally and possibly the most significant trend was how the UFO scientists had constructed the UFO phenomenon as being on course to follow the path of development that other areas of knowledge have followed through history: namely a progression from pseudo-science to eventual inclusion within the boundary of science.