  We present the first results of a project aimed at the combined study of
massive stars and their surrounding nebulae by means of a detailed study of
Galactic HII regions ionized by only one massive star. With this, we intend to
check the validity of the new generation of massive star model atmosphere codes
in terms of ionizing flux distribution. We take into account the effect of the
nebular density distribution in our analyses. Various types of stellar and
nebular observations have been collected for this purpose.
