Abstract. Photoexcitation yields of the 115m In metastable state were measured with Bremsstrahlung γ beams over a range of endpoint energies between 4.5 and 18 MeV. An effective cross section of the 115 In(γ, γ ) 115m In photoexcitation cross section was determined to reproduce the data. This cross section is built from a cross section calculated with the TALYS code, to which an enhancement is added at about 8.5 MeV.