  Based on the AdS/CFT correspondence we study the breaking of the chiral
symmetry in QCD using a simple five dimensional model. The model gives definite
predictions for the spectrum of vector mesons, their decay constants and
interactions as a function of one parameter related to the quark condensate. We
calculate the coefficients $L_i$ of the low-energy QCD chiral lagrangian, as
well as other physical quantities for the pions. All the predictions are shown
to be in good agreement with the experimental data. We also show that they are
robust under modifications of the 5D metric in the IR, and that some of them
arise as a consequence of the higher-dimensional gauge symmetry. For example,
at the tree-level, we find $M_\rho \simeq \sqrt{3} g_{\rho\pi\pi} F_\pi$,
$F_\rho\simeq \sqrt{3} F_\pi$ and BR($a_1\to \pi\gamma)=0$.
