Original: The population of the comune was c. 8,000 in 2004, with the town proper accounting for about half of that; the rest lives in the frazioni of Borgo, Bovara, Cannaiola, Coste, Pigge, Manciano, Matigge, Parrano, Picciche, San Lorenzo and Santa Maria in Valle.
Simplified: The frazioni of Trevi (the smaller towns that belong to Trevi) are Borgo, Bovara, Cannaiola, Coste, Pigge, Manciano, Matigge, Parrano, Picciche, S. Lorenzo, S. Maria in Valle.