We present recent theoretical and empirical results concerning the accuracy of Cepheid distance estimates based on optical and near-infrared (NIR) Period-Luminosity (PL) relations. In particular, we plan to discuss the dependence of both slope and zero-point on the metal content using a large sample of extragalactic Cepheids. Moreover, we discuss pros and cons of optical and NIR reddening free Period-Wesenheit relations. We also mention the impact that GAIA will have on the precision of the Cepheid distance scale and the role that E-ELT will play in the identification of Cepheids beyond the Local Volume.