Thuillier was an honorary professor of the Collège de France and he taught history of artistic creation from 1977 to 1998. He was a renowned specialist of French painting and, along with late Anthony Blunt, the main world authority on Nicolas Poussin.
A collector, he donated, while still alive, along with his brother Guy Thuillier, his collection of drawings (2 000) and engravings (13 000) to the Museum of Fine Arts of Nancy and part of his collection of paintings to the art museum of Vic-sur-Seille. He donated to the city of Nevers part of his archives, his library, a collection of drawings and engravings, his collections of photographes, thus making of the Nevers Médiathèque a documentation centre on the French painting of the 17th century. Another part of this archives and manuscripts is kept at the INHA (fr), in Paris.
- French Painting, Rizzoli International Publications.
- Fragonnard, Rizzoli International Publications.
- Nicolas Poussin (1995) Flammarion, Paris, ISBN 2-08-012440-4
- History of Art (2002) Flammarion, Paris, ISBN 2-08-010875-1