The novel begins with a prologue that brings forward a novel narrated in a form of a folk tale told by the towns people, a relatable parable of all good and all evil. As the story begins we are introduced to the peaceful and serine life of Kino, Juana and their son Coyotito.
As they go about their morning routine we come to realize that Kino and Juana’s relationship is so strong that they need not communicate with words. They listen to the sounds of nature and Kino observes the communion of ants that is mirrored by the village people who all go about their mornings as if in unison.
However that harmony is disrupted as a scorpion climbs up the ropes of baby Coyotito’s hanging box. As Kino slowly approaches the scorpion and Juana prays a native prayer as well as a Hail Mary, the scorpion falls into Coyotito’s box. The scorpion bites Coyotito and injects it’s poison within him before Kino grabs it and crushes it to death. Juana attempts to suck the poison out as the village neighbors rush to the sounds of the baby’s cries.
Juana is strong and collected in the face of disaster and her husband admires her resilience as well as her strong will as she demands a doctor be brought. When the doctor refuses to come Juana and Kino go to visit him themselves and set out to the city with all their neighbors in tow.
As they arrive to his gate, Kino is reminded of the doctor’s ancestors who colonized his own land and is filled with rage. The servant of the doctor is of Kino’s people and as he arrives at the gate Kino tells him of his predicament in their old native language.
The servant leaves to bring news to the fat and lazy doctor who lives a lavish life in a French robe and daydreaming of his return to France. The doctor is angered by the news and refuses to treat Coyotito based on him and his family’s race and the fact that they are poor and further refers to them as no more than mere animals who do not deserve his service.
The servant returns to ask Kino how he intends to pay for the doctor’s services, to which he responds by showing him the few ugly pearls he possesses. The servant then tells Kino that the doctor is not available. Kino then strikes the gate out of anger.
After that the family head to the beach on a new day towards Kino’s canoe that had been passed on to him from generations. The canoe is Kino’s most valuable possession as it kept his ancestors from starving. Juana while on the beach uses seaweed to help reduce Coyotito’s swelling but admits that the doctor’s treatment would be more powerful.
So the three of them set out on an adventure to find some valuable pearls. Kino dives into a sea of oysters and collects them in his net, Kino’s strength allows him to stay underwater longer in order to find the largest and most perfect oysters. Before coming up to the surface, Kino spots a glimmering oyster that is partially opened.
Kino and Juana communicate their hope silently to prevent bad luck. They then open the final oyster to reveal a perfectly rounded pearl that Kino names ‘The Pearl of The World’. The good news continues as Coyotito’s swelling subsides and his situation improves. Kino howls with happiness and the neighbors join them.
The news of Kino’s pearl spreads throughout the town, the doctor announces that he is treating Kino’s son, the pearl dealers prepare themselves for Kino to emerge with the pearl in order to underprice him. It seems that money and greed is all that motivates the town’s people as everyone begins to associate their own hopes and desires in relation to the pearl. The town is filled with the evil forces of greed and envy.
Kino meanwhile has his own dreams as he admits to his brother Juan Tomas that he wants to marry Juana in a church and place Coyotito in school. He then starts to think of more material things like new clothes and a rifle.
After that they are visited by a priest who blesses them and then by the doctor who claims that Coyotito is only getting better before he gets worse. He administers a drug to help him and then leaves, the next day Coyotito has stomach spasms and his state deteriorates. The doctor comes and cures Coyotito and Kino promises to pay him after he sells the pearl. The doctor pretends he does not know of the pearl but looks around to see if he can determine where it might be.
One night, Kino is unable to sleep and is met by an attacker who seeks the pearl. Kino fights back and is left injured. As Juana helps Kino, she tells him of her concern and how she thinks they should dispose of the pearl. Kino tells her that the pearl is their prize possession.
Kino and Juana head to the pearl dealer in order to sell their pearl, as usual with the neighbors in tow. Kino’s brother warns him of the scheming pearl dealers and he is proven right. When Kino approaches the first dealer he offers him 1000 pesos which is fairly underpriced. Kino asks around other dealers who try to cheat him and give him worse deals. He leaves and thinks of going to sell the pearl in the capital. That same night, Kino is attacked once more but refuses to forsake the pearl and asserts his masculinity.
That night, Kino awakens to find Juana running towards the beach in an attempt to dispose of the pearl. Juana is fearless and in a moment of anger, Kino beats her for what she has done. Later that day Kino is attacked once more and the pearl is forced out of his hands. Kino ends up killing the attacker. Juana finds the pearl and despite thinking of disposing of it again, gives it back to Kino.
After the murder, Kino and his family must leave. As they hurry to the canoe, they realize to their dismay that someone must have vandalized it, leaving it with a large hole at the base. Just as Kino is angered by the misfortune, Juana emerges with the news that someone has set their house on fire.
So they rush to Juan Tomas’ house to hide as the people gather around the source of commotion. Juan agrees to protect them but for only one night and advises that Kino dispose of the evil pearl. Kino confesses that the pearl is now a part of him.
After spending a while running away, they finally settle to rest and eat. Kino thinks of his dreams of owning a rifle, then remembers his brutal murder. He thinks of his dream to marry Juana in church, but then remembers the cruel way in which he beat her. And finally he thinks of his dream of giving Coyotito a good education, but only recalls his ill face.
That same night, Kino awakes to the sound of trackers nearby and he and Juana and the baby head to a cave up the hill to hide. However, the trackers are drawn to Coyotito cries. They shoot at the direction of the noise just as Kino kills all three of them. Unfortunately it had been too late and the narrator recalls the tragic ending and the moment the two emerged side by side with a dead baby.
The narrator seems to describe the couple in a state of shock and perhaps a death in life situation. The novel ends as Juana and Kino throw the pearl back into the ocean.