In Jonah Preaching to the People of Niniveh, Salvator Rosa uses a dramatic palette of dark and light colors. The figures are expressive, with Jonah at the center, gesturing passionately to the crowd. The setting is a rugged landscape, enhancing the emotional weight of the scene.

The contrast between the dark sky and the illuminated figures draws the viewer's eye to the action. The painting is executed in oil on canvas, a common medium for the Baroque period. Rosa's technique includes bold brushstrokes and a dynamic composition that captures movement. The dimensions are approximately 150 x 200 cm, making it a significant work in scale.

The use of chiaroscuro emphasizes the figures and creates a sense of depth. Salvator Rosa was known for his dramatic landscapes and historical subjects, often infused with a sense of the sublime. This work reflects his interest in biblical themes and moral storytelling. An interesting fact about this painting is that it showcases Rosa's ability to convey intense emotion through his characters, a hallmark of his style.

It is housed in the Museo del Prado, where it continues to attract attention for its powerful narrative.