If this is a data validation dropdown, it doesn't support autocomplete.
If you can use programming, there are instructions here for adding a
combobox from which you can select one of the values from the data
validation list. In the combobox, you can enable autocomplete:

http://www.contextures.com/xlDataVal11.html


HotRod wrote:
I have built a few dependency lists that have several possible answers in
the drop down box, I'm wondering if it's possible to have the cell "Auto
Complete" as the user types from the list?


--
Debra Dalgleish
Excel FAQ, Tips & Book List
http://www.contextures.com/tiptech.html