It is not easy to identify precisely the origins of the village. Probably the first residential nucleus is identified with Mons Rotarus (round mountain), a center formed between the ninth and tenth century on the homonymous hill, about 5 km from the current urban center. In a document preserved at the State Archives of Naples, Riccardo da Malta is mentioned as the owner in 1250 of the fief of Mons Rotarus, which at the time appeared as a fortified village with a castle and farmhouses. To witness this ancient settlement today remains a square tower, and the remains of a cistern.
Towards the end of the fifteenth century. Mons Rotarus was progressively abandoned by its inhabitants, who downstream, near the small Casal San Pietro, founded the Casalis Novus. In the same period a large Albanian community arrived in northern Puglia, fleeing from Turkish persecution; some of them settled in Casalnuovo, integrating with the inhabitants of the same.
Around 1700 the village passed under the rule of the princes of Bisignano and took the name of Casale Nuovo Monterotaro. Today it is characterized by colorful houses, including a beautiful monumental fountain, a medieval stone farmhouse, the Mother Church of Saints Peter and Nicholas and the Church of Santa Maria della Rocca.