We prove that complete Riemannian manifolds with polynomial growth and Ricci curvature bounded from below, admit uniform Poincaré inequalities. A global, uniform Poincaré inequality for horospheres in the universal cover of a closed, n-dimensional Riemannian manifold with pinched negative sectional curvature follows as a corollary. 0. Introduction Statements of the main results. In this paper, we will establish that complete Rie-mannian manifolds with Ricci curvature bounded below and having polynomial growth, admit a family of uniform Poincaré inequalities. To begin with, let (M n , g) be a complete n-dimensional Riemannian manifold. Henceforth, we will assume that (M n , g) satisfies the Ricci curvature lower bound (0.1) Ricci (M n ,g) ≥ −(n − 1)κ, for some κ ≥ 0. We will also assume that (M n , g) has α-polynomial growth; this means that there exist constants v > 0, α > 0 and R 0 ≥ 0 such that for any m ∈ M n and R > R 0 , the ball of radius R centered at m satisfies (0.2) vol B(m, R) ≤ vR α , where vol denotes the canonical measure on (M n , g). Recall that Bishop's Comparison Theorem (cf. [15, Section IV]) implies that when κ = 0, (M n , g) satisfies polynomial growth with α = n. We will finally assume that the local geometry of (M n , g) is controled in the sense that for any m ∈ M n , (0.3) vol B(m, 1) ≥ ω The triple (M n , dist, vol) with dist being the standard metric induced by the Rie-mannian metric is an example of a metric measure space. Throughout this paper (X, ρ, µ) will denote a metric space endowed with a Borel measure µ. We will use the notation (0.4) u A = 1 µ(A) A udµ,