A chair comprising a base structure comprising a support, a seat connected to the support via a synchronization mechanism and movable with respect to the base structure between a lowered position and a raised position, and a backrest connected to the synchronization mechanism and movable between an upright position, corresponding to the lowered position of the seat, and a backward-inclined position corresponding to the raised position of the seat, wherein the synchronization mechanism comprises two loop-shaped elastic elements spaced apart in a transverse direction and each comprising a lower portion fixed to a rigid support, an upper portion fixed to the seat, a front elastic portion and an essentially C-shaped rear elastic portion that connect the upper portion to the lower portion, wherein the backrest is fixed to the rear elastic portions of the loop-shaped elastic elements.