Hadronic light-by-light scattering in the muon g-2

We briefly review the current status of the hadronic light-by-light scattering contribution to the anomalous magnetic moment of the muon. Based on various model calculations in the literature, we obtain the estimate a_{mu}^{HLbL} = (102 \pm 39) x 10^{-11}. Recent developments including more model-independent approaches using dispersion relations and lattice QCD, that could lead to a more reliable estimate, are also discussed.