We analyze results on π-π scattering using a framework based on nonlinear chiral Lagrangians both at the tree level and at one-loop order. Overall the data can be well understood up to energies of 0.7–0.8 GeV, as well as at threshold, and some of the Lagrangian parameters are well determined. As a side comment, we note that the Skyrmion solution is stable given this experimental fourth-order Lagrangian, but its mass is about 70% too high.