Molinari began his artistic career focused on formalism, but soon discovered the works of Vasarely and was inspired by geometric forms and their rich optical effects.
In 1963, Molinari exhibited his painting La Cuna de Mangle at the Paris Biennial at the Museum of Modern Art.
During his time back in Guayaquil, Ecuador, Molinari reconnected with old colleagues: Enrique Tábara, Aníbal Villacís, León Ricaurte, Gilberto Almeida, Oswaldo Moreno and Guillermo Muñoz and began working with their Group VAN (Vanguardia Artistica Nacional).
He soon developed his own style, inspired by that of his compatriot, Tábara, that fused the tropical nature of his hometown into the informal constructivist geometry, toward the creation of a visual autonomy.
Like other VAN informalists, Luis Molinari sought to honor the history of his homeland with a tribute to Pre-Columbian architecture, as seen in his 1974 painting, Temple of the nuns-Uxmal.