Pietragalla received her ballet training at the Paris Opera's school and joined its company soon thereafter. Her repertoire included solo roles in ballets by Paul Taylor, Carolyn Carlson, Serge Lifar, Maurice Bejart, George Balanchine. Antony Tudor, August Bournonville, Rudolf Nureyev and Rudi van Dantzig.
In 1984 at an International competition in Paris she shared the first prize with Wilfried Romoli. Four years later she earned the title of ballerina. In1990 Pietragalla received the title of an Etoile.
Her repertoire combined choreographic works of the last century with the classics of this century. Pietragalla collaborated with contemporary choreographers, including John Neumeier. William Forsythe. Jose Limon, Roland Petit, Jiri Kylian, Merce Cunningham and Mats Ek. Pietragalla accomplished guest performances around the whole world.
As a choreographer, Pietragalla has created ballets based on the music of Hugues LeBars and Petru Gelfucci. In 1994 she was awarded the title Chevalier des Arts et Lettres, and in 1997 Officier de I'Ordre Nationale du Merite.
In 1998 she assumed the direction of the Ballet National de Marseille and the National Ballet Academy. In the same year Pietragalla was awarded the Benois de la Danse.