  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.
