Oddly, the title is something of a misnomer, as the scope of the movie is not limited exclusively to UFOs, but covers other topics as well, including an animated manned Mars mission scenario, and that (then) up-and-coming conveyance called the space shuttle. Many, many classic UFO still and motion pictures are presented, as well as an interesting and quite thought-provoking segment speculating on life elsewhere in space, and the possible forms that it could take. Much of the movie, however, is filler material, consisting of NASA footage, spacey sound effects, and obtrusive 70s stock music, edited together in a crudely proto-music video-ish style.
In addition to this movie, there are two other Delineator Films documentaries from 1978: "UFO: Top Secret" and "Attack from Outer Space", all narrated by Sid Paul. Why this company would make three movies on the same subject in the same year is a bit beyond me, but, in my estimation, this one is clearly the best of them.