This paper investigates whether in Chestnut (Castanea sativa Mill.) a relationship exists between anatomical features of earlywood vessels, which may contribute to weakening the wood, and the incidence of ring shake. The study compared two groups of 30 wood discs with and without ring shake, collected in three coppice stands in Southern Switzerland. Shake-prone stems are not characterised by more numerous and wider earlywood vessel lumina than the shake-free ones. Hence the hypothesis that ring shake is favoured by the weakening effect of earlywood cell lumina is rejected.