At the age of twelve, he was admitted to the Institute of Fine Arts in Naples, where he studied under Domenico Morelli (1823–1901), a painter of historical scenes who favored dramatic chiaroscuro and vigorous brushwork, and Filippo Palizzi.
His usual subjects included children of the poor, juvenile circus performers, and musicians he observed in the streets of Naples.
His portrait of a young acrobat in Il Saltimbanco (1877–78) captures the fragility of the boy whose impoverished childhood is spent entertaining pedestrian crowds.
His mature works show a brightened palette with a striking impasto technique on canvas and a bold command of pastels on paper.
[2] The first exhibition in the U.S. devoted exclusively to Mancini's work was at the Philadelphia Museum of Art, October 20, 2007 – January 20, 2008, a museum which owns fifteen oil paintings and three pastels by Mancini that were a gift of New York City art dealer Vance N. Jordan.