We will show optimal regularity for minimizers of the Signorini problem for the Lame system. InThen u ∈ C 1,1/2 (B + 1/2 ). Moreover the free boundary, given by Γu = ∂{x; u 3 (x) = 0, x 3 = 0} ∩ B 1 , will be a C 1,α graph close to points where u is not degenerate.Similar results have been know before for scalar partial differential equations (see for instance [4] and [5]). The novelty of this approach is that it does not rely on maximum principle methods and is therefore applicable to systems of equations.