We are undertaking a multi-wavelength study of a sample of 20 luminous IRAS sources in the southern hemisphere that are thought to be representative of young massive star-forming regions. Our goal is to understand the characteristics of the ionized gas associated with the earliest phases of massive star birth. In particular whether the formation of an HII region is quenched by dust very early on and whether the small sizes of ultra-compact HII regions do indeed signify a young age. Our study incorporates sensitive ATCA radio continuum data, SEST 1.2-mm continuum and line data, mid-infrared TIMMI2 data as well as data taken from the MSX database. The objects in our sample have been chosen from the Galaxy-wide survey of CS(2-1) emission towards IRAS sources with IR colours typical of compact HII regions containing at least an embedded star (Bronfman et al 1996). All of the sources exhibit CS line profiles indicative of either outward or inward motion and in some cases bipolar outflows (Mardones 1998). Two sources in our sample were found to have no detectable radio emission (down to 2 mJy) in the survey by Walsh et al 1998), making them candidates for massive stars in a very early evolutionary phase, prior to the onset of an ultra compact HII region. We present new observational findings from our study to date