Crystal structures were obtained from X-ray powder patterns. The magnetic properties were investigated between 4.2 and 300K by magnetization measurements and neutron diffraction. Both compounds show spin-glass transitions at low temperatures. In CrNbO4, the cusp in the susceptibility is observed at 9.3K. At higher temperatures, the Curie-Weiss law is obeyed and the moment of the Cr3+ ions is (3.85+or-0.02) mu B. FeTaO4 shows a field-dependent susceptibility similar to that observed in dilute random alloys. The Curie-Weiss law is not obeyed within the temperature region investigated.