His style differed from other primitive painters and he was ridiculed by more traditional artists, but found appreciation from those outside the establishment. Jean Huge, Picasso and the surrealist movement, were fans of Rousseau's work. The artist frequently painted jungle scenes, he used botanical gardens for his inspiration as he had never having seen a jungle in real life. To gain his perspective of the jungle Rousseau studied illustrated books and the taxidermy of wild animals. He even interviewed soldiers that had toured the Mexican jungles to learn about their experiences of the subtropics. It was claimed he had been to the Mexican jungles himself, however; it is not true. In fact, he had never left France.

Rousseau's work often featured oversized plant life and wild animals hiding in the shadows or foliage of the jungle. He developed the portrait landscape painting style, in which he would depict his subjects in the centre of a landscape painting. During his lifetime he was ridiculed for this, but now he is thought of as a self-taught genius. His work has a high artistic quality, and has been a source of inspiration to animated films, such as Madagascar.

Jungle Sunset is one of Rousseau's wildlife paintings. Created in 1910, it is an oil on canvas painting that was completed close to the artist’s death. It features his preferences in colour scheme, tone and mood that are frequently used in his artwork. In the centre of this landscape picture, there is the outline of a black man being jumped on by a jaguar. The male figure appears to be cowering under the attack, while the jaguar has pounced up, to the man’s chest height. They are camouflaged by the large grass and the surrounding leaves. Above them, an orange sun sits low in the pale blue sky.

The lush plants in the picture are not an accurate image of tropical vegetation. Rousseau used specimens taken from the Jardin des Plantes as his basis for jungle vegetation and then enlarged these plants to create his jungles. If looking closely at the trees, it is clear they are magnified ferns. The flowers in the picture are far bigger than they realistically should be. They rise well above the head height of the man and the jaguar, when in reality it would be unlikely for them to be above knee level.