  We present high-resolution HI data obtained using the Australia Telescope
Compact Array to resolve the near/far distance ambiguities towards a sample of
compact HII regions from the Red MSX Source (RMS) survey. The high resolution
data are complemented with lower resolution archival HI data extracted from the
Southern and VLA Galactic Plane surveys. We resolve the distance ambiguity for
nearly all of the 105 sources where the continuum was strong enough to allow
analysis of the HI absorption line structure. This represents another step in
the determination of distances to the total RMS sample, which with over 1,000
massive young stellar objects and compact HII regions, is the largest and most
complete sample of its kind. The full sample will allow the distribution of
massive star formation in the Galaxy to be examined.
