Saint Simon is depicted over a dark background. He carries a book and the saw that symbolizes his martyrdom.

The technique, with strong contrasts of light and shadows, is still tenebrist, following the style of the Italian painter, Caravaggio, who was the maximum influence on Ribera's work. That same influence is visible in the naturalist representation of the saint's face, which may have been based on human types in Ribera's everyday life.

This type of composition, a half-length depiction of a saint on a dark background, accompanied only by his iconographic attributes, was abundant in Ribera's work from the sixteen thirties.