As in Siena, it is a horse-race that brings together Historical Centre's areas.
The riders, dressed according to the colours of their rione, ride bareback and have to cover 4 times the course.

The first race which took place in the Garibaldi Square was on the 5^th of June of 1864, simple horse-race "in a circle, in the Roman style", during the Chiocane's fair (the cherries bunch's fair).
It became a real palio bringing together the rioni in 1935.

During the world wars, the Palio was suspended, but went on again as before from 1946.

It takes place in the Castiglionese Week (third Sunday in June), consecrated to the Madonna delle Grazie, during which there are also sportive and theatrical events.
The programme of the festivities is as follows:

• Saturday: Riders and horses qualifying rounds.
  Rustic procession.
• Saturday evening: Propitiation dinner in each rione.
• Sunday morning: Horses blessing and jockeys nomination.
• Sunday afternoon: Cortège historique en costumes.
• 18.30: the Palio.

After the race, the inhabitants of the rione that won render thanks to the Madonna del Rivaio in the homonymous Chapel, and then claim their joy everywhere in Castiglion, and feast until the break of day.

The next week is organized the Victory Dinner, in the winner rione.