Prata Camportaccio is a comune (municipality) in the Province of Sondrio in the Italian region Lombardy, located about 100 kilometres (62 mi) north of Milan and about 40 kilometres (25 mi) northwest of Sondrio. As of 31 December 2004, it had a population of 2,758 and an area of 27.9 square kilometres (10.8 sq mi).