The L p (1 < p < ∞) and weak-L 1 estimates for the variation for Calderón-Zygmund operators with smooth odd kernel on uniformly rectifiable measures are proven. The L 2 boundedness and the corona decomposition method are two key ingredients of the proof. 1 2 ALBERT MAS AND XAVIER TOLSAConcerning the notion of uniform rectifiability, recall that a Radon measure µ in R d is called n-rectifiable if there exists a countable family of n-dimensional C 1 submanifolds {M i } i∈N in R d such that µ(E \ i∈N M i ) = 0 and µ ≪ H n , where H n stands for the ndimensional Hausdorff measure. Moreover, µ is said to be n-dimensional Ahlfors-David regular, or simply n-AD regular, if there exists some constant C > 0 such thatfor all x ∈ suppµ and 0 < r ≤ diam(suppµ). Note that if diam(suppµ) < +∞ then µ(R d ) < ∞ and so the condition µ(B(x, r)) ≤ Cr n in the definition of AD regularity actually holds for all r > 0. Finally, one says that µ is uniformly n-rectifiable if it is n-AD regular and there exist θ, M > 0 so that, for each x ∈ suppµ and 0 < r ≤ diam(suppµ), there is a Lipschitz mapping g from the n-dimensional ball B n (0, r) ⊂ R n into R d such that Lip(g) ≤ M and µ B(x, r) ∩ g(B n (0, r)) ≥ θr n , where Lip(g) stands for the Lipschitz constant of g. In particular, uniform rectifiability implies rectifiability. A set E ⊂ R d is called n-rectifiable (or uniformly n-rectifiable) if H n | E is n-rectifiable (or uniformly n-rectifiable, respectively).We are ready now to state our main result. In the statement M (R d ) stands for the Banach space of finite real Radon measures in R d equipped with the total variation norm.Theorem 1.1. Let µ be a uniformly n-rectifiable measure in R d . Let K be an odd kernel satisfying (1) and, for ρ > 2, consider the associated variation operator defined in (3). ThenThe variation operator has been studied in different contexts during the last years, being probability, ergodic theory, and harmonic analysis three areas where variational inequalities turned out to be a powerful tool to prove new results or to enhace already known ones (see for example [1,8,9,10,11,13,18], and the references therein). Inspired by the results on variational inequalities for Calderón-Zygmund operators in R n like [2, 3], in [16] we began our study of such type of inequalities when one replaces the underlying space R n and its associated Lebesgue measure by some reasonable measure in R d , being the Hausdorff measure on a Lipschitz graph a first natural candidate. In this regard, Theorem 1.1 should be considered as a natural generalisation of variational inequalities for Calderón-Zygmund operators in R n from a geometric measure-theoretic point of view.A big motivation to prove Theorem 1.