Despite their important luminosity, massive stars keep unveiled most of their formation mainly because they are deeply embedded within their native cloud. This difficulty is accentuated by their small number and by their larger distances compared to low mass stars. This explains why models for the various stages of their formation are still in their infancy. We briefly present here the initial conditions and the most common models for the formation of massive stars. Also, we focus onto a family of self-similar models that allow accretion and outflows around massive protostars. Finally, we try to sketch the temporal evolution of massive star formation.