Rudolpho Anaya's Heart of Aztlán follows the Chávez family, a Chicano family moving from Gaudalupe, New Mexico to a barrio on the outskirts of New Mexico called Barelas. The title comes from the name of the mythological Aztec homeland, and the Chavez family members struggle—each in their own way—to identify their homeland. "Aztlán" was also a popular term in various movements for Chicano rights throughout the twentieth century. The major characters of this story are the members of the Chávez family.

The paterfamilias, Clemente Chavez, works for the railroad in the city, but loses his job as the result of a strike. The family members—three boys and two girls—each face different hardships. The father turns to alcoholism, his youngest is killed, and his daughters turn to prostitution.

Clemente's son Jasón misses his native town, but he finds peace in the city by befriending a local girl whose father has died. The youngest son, Benjie Chávez, becomes involved in drugs and is killed by the end of the novel.

Crispin, a spiritual healer (popularly known as a curandero), rescues Clemente after he has had too much to drink. Crispin is a blind musician who plays music for the workers in the railroad yard. Crispin's figure is an archetypal "benevolent guide" or "sage" (a characteristic that is underscored by his blindness). Crispin helps Clemente find power inside of himself to find peace in his new home in the barrio.

Jasón Chávez also makes an appearance as a minor character in Anaya's first book in the trilogy, Bless Me, Ultima (published in 1972).