Degradation of amoxicillin (AMX) was achieved using pillared montmorillonite ferric oxalate (PMFeOx) catalyst in photo-Fenton process. The catalyst was prepared by aluminum pillaring of mild acid treated montmorillonite (MATM) clay followed by incorporation of ferric oxalate. The PMFeOx catalyst produced was characterized. XRD results revealed the intercalation of aluminum with an increase in basal spacing from 1.24 to similar to 1.69 nm, the specific surface area also increased from 164.94 to 211.61 m(2) g(-1). SEM images of PMFeOx showed the formation of irregular flaky morphology with random orientation. The FTIR profile at relevant wavenumbers detected intercalation of aluminum and incorporation of iron. The optimum condition that achieved 99.65% and 84.26% initial concentration reduction and COD removal respectively, for 40 ppm AMX solution was 15% excess H2O2 and 2.0 g PMFeOx catalyst loading at 40 degrees C in 10 min. The catalyst displayed good efficiency in degrading amoxicillin. (C) 2011 Elsevier By. All rights reserved.