2003 map with Prato-Sornico.

Prato-Sornico is a former municipality in the district of Vallemaggia in the canton of Ticino, Switzerland. The district of Vallemaggia is a district of the canton of Ticino in Switzerland. Canton Ticino or Ticino ( Italian: tiˈtʃiːno French and German: Tessin and) is the southernmost canton of Switzerland (English pronunciation; Schweiz Swiss German: Schwyz or Schwiiz Suisse Svizzera Svizra officially the Swiss Confederation

The municipality contained the villages Prato and Sornico. Prato is a village and former municipality in the district of Vallemaggia in the Canton of Ticino, Switzerland. Sornico is a village and former municipality in the district of Vallemaggia in the Canton of Ticino, Switzerland. These entities were former municipalities of their own, having been merged to form Prato-Sornico in 1864.

In 2004 Prato-Sornico municipality was merged with the other, neighboring municipalities Broglio, Brontallo, Fusio, Menzonio and Peccia to form a new and larger municipality Lavizzara. Broglio is a village and former municipality in the district of Vallemaggia in the Canton of Ticino, Switzerland. Brontallo is a village and former municipality in the district of Vallemaggia in the Canton of Ticino, Switzerland. Fusio is a village and former municipality in the district of Vallemaggia in the Canton of Ticino, Switzerland. Menzonio is a village and former municipality in the district of Vallemaggia in the Canton of Ticino, Switzerland. Peccia is one of six small Swiss municipalities which merged in April 2004 to form the commune of Lavizzara, with about 1000 people Lavizzara is a municipality in the district of Vallemaggia in the canton of Ticino in Switzerland.