In this paper, we discuss the existence of nonexpansive retraction onto the set of common fixed points. Assume that φ={Ts:s∈S} is an amenable semigroup of nonexpansive mappings on a closed, convex subset C in a reflexive Banach space E such that the set F(φ) of common fixed points of φ is nonempty. Among other things, it is shown that if either C has normal structure, or the Ts’s are affine, then there exists a nonexpansive retraction P from C onto F(φ) such that PTt=TtP=P for each t∈S and every closed convex φ-invariant subset of C is also P-invariant; in the case that the mappings are affine, P is also affine, and Px∈co¯{Ttx:t∈S} for each x∈C, and it is unique regarding the latter property. Our results extend corresponding results of [T. Suzuki, Some remarks on the set of common fixed points of one-parameter semigroups of nonexpansive mappings in Banach spaces with the Opial property, Nonlinear Anal. 58 (2004), 441–458] and [R. E. Bruck, A common fixed point theorem for a commuting family of nonexpansive mappings, Pacific J. Math. 53 (1974), 59-71].