Inverse opal photonic crystals of Yb3+, Er3+ co-doped CaTiO3 (CaTiO3:Yb, Er) were prepared using self-assembled polystyrene templates combined with the infiltration of sol-gel precursor. The influence of the photonic band gap on upconversion emission of Er3+ has been investigated in the CaTiO3: Yb, Er inverse opals. Significant reduction of the upconversion emission was detected if the photonic band-gap overlaps with the Er3+ ions emission band. (C) 2011 Elsevier B.V. All rights reserved.