The thermal waters of Chianciano, known already to the Etruscans and the Romans, were appreciated in the Middle Ages too, and were visited by such famous personages as Charlemagne. In Medicean times, during the Grand Duchy of Cosimo III, the thermal establishment was rebuilt for the first time, to be renovated still further during the 18th century. But it was above all in the 19th and 20th centuries that Chianciano developed and flourished as a health centre and resort town.

The waters of Chianciano had attracted the interest of physicians and naturalists since the Middle Ages. In 1334 Simone di Messer Iacopo Tondi, visiting Chianciano on a mission for the Sienese government, observed that "The Bath of Clanciano is useful for curing many illnesses." But it was only starting from the second half of the 18th century, subsequent to progress achieved in chemistry, that the first strict analyses of mineral waters were conducted. Those of Chianciano were studied by, among others, Giuseppe Baldassarri in 1756 and Antonio Targioni Tozzetti in 1833.

Today Chianciano Terme is still a renowned locality. The therapeutic properties of its waters make it, in fact, one of the best-known places for treating disorders of the liver.