Slodtz spent seventeen years in Rome, where he was chosen to execute a statue of St. Bruno (1744) for a niche in the nave of St Peter's.

The statue demonstrates the saint's refusal of the bishop's miter and staff offered by a cherub, while his right hand rests on a skull, evoking mortality.

The simplicity of the monk's robes and the shaved head adds classical style to the heavily baroque sculpture.

Other Roman churches showcase his work including San Luigi dei Francesi and Santa Maria della Scala.

After his return to France in 1747, Slodtz, in conjunction with his brothers, Antoine-Sebastien and Paul, produced many decorative works in the churches of Paris, and, though many have been destroyed, his most acclaimed achievement is the tomb of Jean-Joseph Languet de Gergy at St. Sulpice, which was commissioned in 1750.