Abstract In this comment, we review the work by Xie [Phys. Status Solidi B 246 , 2257 (2009)] on electric field effects and nonlinear optical properties of excitons confined in spherical quantum dots. We find an inconsistency in the calculation of the dipole moments, which lead to vanishing nonlinear optical results. For the same set of parameters studied by Xie, we obtain new and reliable optical rectification coefficients via a finite element approach.