A simple method to determine nonradiative recombination coefficients of vertical‐cavity surface‐emitting lasers is proposed and demonstrated. The dependence of the lateral spontaneous emission on the current density is used to determine the nonradiative recombination coefficients and the threshold carrier densities. In this scheme, the lateral spontaneous emission obtained from the nearest neighbor devices is analyzed. For 10‐&mgr;m diameter proton‐implanted vertical‐cavity surface‐emitting lasers, the obtained nonradiative recombination coefficient is about 1.8×108s−1, responsible for 25% of threshold current density. ©1995 American Institute of Physics.