=MAX(IF(Sheet2!supplier_range=supplier,Sheet2!date _range))

which is an array formula, it should be committed with Ctrl-Shift-Enter, not
just Enter.
Excel will automatically enclose the formula in braces (curly brackets), do
not try to do this manually.
When editing the formula, it must again be array-entered.

--
HTH

Bob

(there's no email, no snail mail, but somewhere should be gmail in my addy)

"drumbumuk" wrote in message
...
I hope this makes sense:

In sheet1 there is a list of suppliers. In sheet2 there is an evaluation
form, in which users select the supplier used from a drop-down list
(sourced
from sheet1) then go along the row to grade the supplier accordingly. One
field in the record is Date Used. What i want to do is this...

Get excel to look up all instances/records of the company in sheet2, then
return the last date used to sheet1.

Any help gratefully received.