Abstract A modification of Feynman rules is developed such that the high-energy asymptotic forms of individual Feynman diagrams or of the complete n-point functions are obtainable. The modifications are similar to those discovered by Weinberg in connection with the dynamics at infinite momentum. The present techniques are used to obtain the high-energy behavior of the vertex of spinor electrodynamics. It is suggested that the result on the mass shell and large, spacelike momentum transfers is exp − e 2 16π 2 log 2 ∥k 2 μ 2 when all crossed diagrams are included. The off-mass-shell asymptotic form is also obtained and found to agree with previous results. The Bethe-Salpeter kernel, occurring in the integral equation for the vertex, is given in the relevant energy regions.