A chair includes two armrest units and a leg assembly. The leg assembly comprises a front leg unit having a pair of front legs pivoted to each other, and a rear leg unit having a pair of rear legs pivoted to each other, and being operable to be disposed in one of a folded state and an extended state. Each armrest unit includes an armrest with two opposite ends respectively pivoted to a respective one of the front legs and a respective one of the rear legs. A seat unit is connected to the armrest units. A pair of inclination-preventing members project respectively from the armrest units and abut against the front and rear leg units, respectively, when the leg assembly is disposed at the extended state.