  Observational evidence for inflowing motions in massive star forming regions
has been extremely rare. We have made a spectroscopic survey of a sample of 28
massive star forming cores associated with water masers. An optically thick
line of HCN (3-2) was used in combination with optically thin lines [H^{13}CN
(3-2) or C^{34}S (5-4), (3-2), and (2-1)], to identify ``blue'' line profiles
that can indicate inflow. Comparing intensities for 18 double-peaked line
profiles yields 11 blue and 3 red profiles that are statistically significant.
In the full sample of 28 sources, 12 show blue profiles and 6 show red profiles
that are statistically significant based on the velocity offsets of lines that
are optically thick from those that are optically thin. These results indicate
that HCN (3-2) emission may trace inflow in regions forming high-mass stars.
