Chestnut is not an easy species by the dendrochronological point of view because of a quite erratic behaviour in the ring chronologies, the lack of reference chronologies to have dating and because of the few rings which are present even in the large sized timbers. In Santa Maria Nuova sampling according to the dendrochronological standards was performed in the main, in the secondary roof frameworks and in old painted joist these last were discharged during the restoration work because of the bow and because of the disappearing of the painted layers. Dendrochronological groups were built and some samples were chosen in order to be dated by C14 (wiggle matching method).Wood assortments of XII century were found in the main roof (ties and rafters) and in the secondary roof frameworks, so as it was possible to date the timber which was located during some restoration works. The painted joists are dated in the XV century.