Data on inclusive pion and eta production measured with the dielectron spectrometer HADES in the reaction p + Nb-93 at a kinetic beam energy of 3.5 GeV are presented. Our results, obtained with the photon-conversion method, supplement the rather sparse information on neutral-meson production in proton-nucleus reactions existing for this bombarding energy regime. The reconstructed e(+)e(-)e(+)e(-) transverse-momentum and rapidity distributions are confronted with transport-model calculations, which account fairly well for both pi(0) and eta production.