The tourist office is at Via Porsenna 79, 53043 Chiusi (tel. 0578-227-667; www.prolocochiusi.it). April through September it's open Monday to Saturday from 9am (10am Sept) to 1pm and 3 to 6pm, and Sunday from 9am (10am Sept) to 1pm only. October hours are daily 10am to 2pm; November through March it's open daily 10am to 1pm.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.