Imaginero is an ethnobiography of Hermógenes Cayo, a self-taught woodcarver and painter who lives on the high Andean plateau of Argentina. The film portrays Hermógenes, his wife Aurelia Kilpe, and their children in their Andean lifestyle, as well as Hermogenes' passion for painting, carving, building, and his devotion to the Virgin Mary.

Devout, austere and dedicated to craftsmanship, he can make anything from religious figures carved from cactus wood to a working harmonium. Inspired by a trip to Buenos Aires to advocate for land rights, Hermógenes has labored to replicate the style of the capital's grand cathedral and shrine to the Virgin with resourcefulness and skill.

A respected member of his community, the image-maker's wedding ceremony brings music, costumes and dancing, while Prelorán films life, festive and ordinary, on the coldest part of the plateau. Hermógenes and his family live much as their ancestors have always done, raising sheep and weaving cloth, but a train now makes the rest of the world closer; “the children play differently now that they have been to town,” he notes.

The film does not follow a traditional narrative structure, transitioning between themes and revisiting earlier themes later. In this way the film weaves a portrait of Hermógenes Cayo, the craft of image making, an indigenous Catholicism, as well as portraying the lifestyle of a solitary Andean family braving the harsh conditions of their surroundings. The relationship between individual and culture, as well as cultural change, is artfully expressed by Prelorán.