Sn−Li exchange equilibria have allowed the quantification of the stabilizing effect of cation−π interactions in organolithium chemistry. Stabilization energy data on the effect of Li−π complexation of an aromatic ring or a CC double bond in organolithium compounds are presented. The amount of stabilization gained by complexation of the Li atom with a π system in α-oxy-organolithium compounds is quite comparable to the one observed in systems containing Li−N or Li−O interactions.