hi, David !
> I have a dynamic range list but there are many duplicates within 900+ entries.
> Is there anyway to prevent duplicates from showing in a dropdown?
AFAIK, if you don't want duplicate records in your dropdown list...
-> duplicate records *must* NOT be in your dropdown-source list
try with advanced filter, unique and copy to another location
-> and make the new location the source range for your dropdown list
hth,
hector.