  We present recent results concerning distance determinations based on the two
most popular primary distance indicators, namely classical Cepheids and RR
Lyrae. We discuss the problems affecting the Cepheid distance scale, and in
particular the dependence of fundamental Period-Luminosity (PL) and
Period-Luminosity-Color (PLC) relations on the metal content. The key
advantages in using the K-band PL relation of RR Lyrae stars when compared with
the M_V vs [Fe/H] are also presented.
