Photocatalytic activity of spinel type complex oxides has been investigated in this study. Alkaline earth ferrites AFe2O4 (A = Ba, Ca, Sr) were synthesized by sol-gel method. Structural characterizations reveal that the synthesized ferrites have orthorhombic crystal structures with different space groups and cell dimensions when they have different alkaline earth metals in their A site. All the synthesized ferrites exhibited their bandgap in the range 2.14-2.19 eV. Their photocatalytic activities were studied using congo red dye under sunlight and xenon lamp radiation. The substitution of Ba, Ca and Sr at A site of these ferrites had varying impact on dye degradation process. Under xenon lamp irradiation, BaFe2O4 exhibited the highest percentage of dye degradation (92% after 75 min). However, CaFe2O4 showed the fastest degradation of the dye (70% within 15 min). In the absence of irradiation, SrFe2O4 showed the highest dye adsorption (44% after 75 min). © 2016 Elsevier B.V. All rights reserved.