Abstract The correlations by linear free energy relationships (LFER) of published equilibrium and rate data on metal extraction by organic compounds are discussed. The extraction equilibria concerning one metal and a series of structurally related extractants can be successfully correlated by the Hammett or Taft equations. For rate data, the correlation with partition coefficients of the extractants between organic phase and water, estimated from structural fragments, seems to be possible. The requirements on the quality of rate data are discussed. The approach is promising with respect to the prediction of extractant performance.