The efficiency of LaFeO3 and Cu-doped LaFeO3 nanopowders in the photocatalytic degradation of ibuprofen (IBP) has been investigated. Aqueous solutions of IBP were irradiated under visible-light in the presence of the catalyst and H2O2. The experiments were carried out on aqueous suspensions containing 5.0 x 10-5 M of IBP, 0.003 M of H2O2, 0.130 g L-1 (5.0 x 10-4 M) of catalyst. The composition of the reaction solution was monitored during the experiments by UV-Vis spectroscopy and HPLC. The results showed a higher photocatalytic activity of Cu-doped LaFeO3 (5 and 10 mol%) compared to pure LaFeO3. The concentration of 4-isobutylacetophenone (4-IBAP), an harmful by-product of the degradation of IBP was the lowest when using 5 mol% Cu-doped LaFeO3 catalyst, i.e. ( 2 % and << 1 % of the initial IBP concentration after 5 h and 24 h of irradiation, respectively. The chloride water matrices decreased the degradation percentage of IBP and 4-IBAP.