The interior of the theatre has a horseshoe shape with 36 boxes distributed on three levels, and is richly decorated with mythological themes. In 1885 it was inaugurated with the operas by the Sinalunghese Ciro Pinsuti, after whom the theatre was named.
In this way, Sinalunga came to be equipped with one of the most beautiful theatres in southern Tuscany, enlivened by amateur dramatics and music companies. In the early 20th century, the premises of the cafeteria, kitchen and ballroom were purchased. Following this flourishing period came the First World War and the advent of cinema which led the theatre along a period of slow decline that culminated in 1984 when it was declared unfit for use.
In 2002, it was bought by the municipal administration who undertook a substantial recovery project that enabled its reopening.