The Martian Chronicles takes place on a populated Mars, with a Martian society they loosely reflects the human society on Earth. One night, a Martian woman dreams that a rocket comes out of the sky and lands on Mars; a light skinned man with clear blue eyes is inside the rocket, a human by the name of Nathaniel York. When the rocket lands, her husband is wary and fearful of the passenger and shoots him. Meanwhile, all over Mars people are beginning to have similar dreams, and they are also starting to sing songs that are popular on Earth. A second rocket lands carrying more astronauts, who disembark and start to explore. When they tell the Martians they are from Earth, everyone believes they are actually all insane and that their rocket was a hallucination, so they are all shot by a psychologist who believes them to be irretrievably mentally damaged.
Whilst this is happening on Mars, a third rocket is getting prepared for flight back on Earth. This rocket lands on Mars in what appears to be the perfect American small town, white picket fences and all. The astronauts meet their relatives who have passed then go their separate ways to eat dinner with their lost parents and siblings. As he is going to bed next to the brother he lost many years before, it occurs to him that these reunions are in actual fact traps set by the Martians; his "brother" kills him before he is able to make his escape.
A fourth voyage takes off from Earth a year later, landing successfully on a Mars that is now deserted as almost all of the Martians perished from chicken pox contracted after one of the previous landings from Earth. Captain Wilder is in celebratory mood, allowing his men to dance and drink, angering Jeff Spender, the crew's archaeologist. Spender is a "throwback" to the great archaeologists and explorers of generations past. He has innate respect for any civilizations, including the Martian civilization, and is offended by the crew's partying; he believes they should be conducting themselves in a far more dignified manner with respect that befits their surroundings and their mission. This anger precipitates psychotic rage and Spender tries to kill the rest of the crew. Wilder realizes his actions have contributed to Spender's mental demise and attempts to reason with him, showing sympathy for his position, but is finally forced to shoot him.
Gradually settlers start arriving on Mars, attracted by the promise of work and new possibilities. Benjamin Driscoll is given a job planting trees, and is amazed to see a landscape that was once barren has become green. Tomas Gomez, another settler, encounters one of the few remaining Martians but is unable to touch or communicate with him; he believes they both exist on different time planes. The first settlers are gritty and tough, and construct small towns that are just like American towns, usually built around a church. Children on Mars play in ruins and make music by banging the abandoned bones of Martians together. William Stendahl is upset that the new government of Mars has banned all tales of fantasy. He constructs a replica of the House of Usher, then invites the government officials responsible for this ban to a party where he systematically kills them.
Eventually Mars begins to resemble a retirement community. One couple miss their son, Tom, who has died, terribly; one day, he appears at their porch, but of course he is not really "their" Tom, but a Martian who is able to metamorphose into whichever person those around him wish him to be. Everyone believes him to be "their" person and consequently many fights over him take place.
News arrives from Earth warning of an imminent atomic war. On Mars, hotdog stand proprietor Sam Parkhill, a member of Captain Wilder's expedition, is approached by a group of Martians that he kills, but more arrive and subdue him. To his puzzlement, they give him their deeds for half of Mars; later that night he sees Earth burst into flames and understands their action. Throughout Mars, people watch the situation on Earth until the message "Come Home" is heard on a radio signal. Walter Gripp, an Oldsmobile who is a mountain-dweller, is left behind and is desperate for female company, but is repelled by the woman he finds, Genevieve Selsor.
The novel fast forwards twenty years; Hathaway still lives on Mars, with his family, awaiting rescue. Finally a rocket lands, piloted by Captain Wilder, who has been exploring Jupiter and Pluto. Wilder sees the shack the family live in and observes the difficult conditions which make it all the more perturbing that Hathaway and his family have not ages in the intervening twenty years. Suddenly Hathaway does of a heart attack just as Wilder realizes they are robots.
On Earth, the nuclear war killed most people but the houses continue to operate the way they always did; the washing machine keeps washing, music continues to play, lights switch on and off. A family arriving on Mars have escaped the nuclear wasteland that is Earth; the father tells his sons thru are now Martians. Soon another family arrives with daughters, opening up the potential for the creation of a new generation on Mars.