When the scientist Fechner disappears in the surface of the mysterious Solaris Ocean, the experienced helicopter pilot Henri Berton crosses a fog seeking out Fechner and has weird visions. His statement is presented to a commission of scientists that believe he had hallucinations. However, the widowed psychologist Kris Kelvin is assigned to the space station that orbits Solaris to check the mental health of the three remaining scientists that are still working there. He first meets Dr. Snaut, who tells him that Dr. Gibarian committed suicide, and later he meets Dr. Sartorius and he realizes that the scientists have strange behaviors. When he encounters his wife Hari, who died ten years ago, in the space station, the scientists explain to Kris that the Solaris Ocean has the ability to materialize the innermost thoughts in neutrons beings. Kris questions whether the appearance of his beloved wife is a curse or a blessing.
Hari: I have a feeling someone's deceiving us.
Hari: Did you ever think of me? Kris Kelvin: Only when I was sad.
The movie is based on the novel by Polish author Stanislaw Lem.
A number of sources claimed that Soviet officials withheld the 165-minute version from export. Mosfilm did indeed issue this version for export, and subtitled prints were being shown in the United States in 1973.
This was the most widely seen of Andrei Tarkovsky's films outside of the Soviet Union. However, Tarkovsky himself reportedly considered it the least favorite of the films he directed.
A print was screened at the Cinema Village theater in New York City in the mid-1980s that combined an English-dubbed version of the film with sequences from a Russian-language print. This version also featured cheesy 1970s-era titles. Around this time, this was considered the most complete version of the film available in the United States. It was not until the re-opening of New York's Film Forum theatre in 1989 that the complete and uncut Russian-language version was shown there theatrically.
The extended scene following Berton as he rides back to the city was filmed in Osaka and Tokyo. Foreign travel was not easily approved, and the reason this long scene was left in the movie was probably to justify that trip for the director and crew. A Japanese city circa 1970 may not look very futuristic to modern audiences, but its impression on Soviet viewers at that time of the film's release was probably quite different. Tarkovski's diary reveals that they just missed the World's Fair, and they may have planned to shoot footage at it that would have looked far more futuristic.