Updated: May 18, 2024

Allen produced a series pilot, "No Place to Hide." After CBS accepted the series the characters Smith and the Robot were added. The ship was redesigned with a second deck, and named the Jupiter-2. ( It had been the Gemini 12 ) For budget considerations, a good part of the pilot episode was reworked into the early series episodes. CBS was also offered Star Trek at around the same time, but it was turned down in favor of Lost in Space.

The Lost in Space TV series was originally named Space Family Robinson. Allen was apparently unaware of the Gold Key comic of the same name and similar theme. His series was, as was the comic, a space version of "Swiss Family Robinson" hence the title similarity. Gold Key Comics had the opportunity to sue Allen's production company and the 20th Century Fox studio for copyright infringement but as Allen was expected to win the rights to other Gold Key licenses and had already produced their Voyage to the Bottom of the Sea series, a deal was arranged. Not only was the name changed to Lost in Space but two extra characters, Doctor Zachary Smith, and the Robot, were added to ensure a greater difference between the comic and series.

The first season emphasized adventure. It chronicled the daily adventures that a pioneer family might well experience if marooned on an alien world. These included dealing with dangerous native plants and animals, and off-world visitors. In the first season, only the special effects shots were filmed in color, in anticipation of reusing shots in color seasons.

The second season aired in the same time slot as ABC's Batman, and it has been suggested that the camp tone was adopted to compete with Batman. There was a growing emphasis on Smith, Will and the Robot at the expense of the other characters. Smith's change in character was not appreciated by the other actors. According to Billy Mumy, Mark Goddard and Guy Williams disliked the shift from serious science fiction.

The third season had more adventure, but episodes like "The Great Vegetable Rebellion" with actor Stanley Adams as Tybo, the talking carrot still demonstrated humorous fantasy. Other episodes were whimsical and emphasized humor, including fanciful space cowboys, space hippies, pirates, and a beauty pageant.

During the first two seasons, episodes concluded in a "live action freeze" anticipating the following week, with the cliff-hanger, "To be continued Next Week! Same Time - Same Channel!". There was little ongoing plot continuity between episodes, except in larger goals; for example, to get enough fuel to leave the planet. For the third season, the episode would conclude, and then a "teaser" for viewers to "Stay tuned for scenes from next week's exciting adventure!" would show highlights from the next episode just before the closing credits began.

After cancellation, the show was successful in reruns and in syndication for many years, most recently on FX, Sci-Fi Channel, and ALN.

Stylistically, the series was of high quality, featuring what was expected for space travel at the time; eye-catching silver, tapered spacesuits, laser guns and spectacular props and sets.