You can't do a conditional average across multiple sheets using that
function. There are other formulas you could use but they are pretty long
and complex.

To keep things simple I would just use an additional cell with a formula on
each sheet like this:

=IF(D1235,D12,"")

Then just get the average of those cells:

=AVERAGE(Sheet1:Sheet8!A1)

--
Biff
Microsoft Excel MVP


"TPaton" wrote in message
...
I am trying to create a formula on a 'summary' sheet that will be the
average
of the same cell on a series of 'detail' sheets. Using the AVERAGEIF
formula
would appear to be the answer, but I get a #VALUE error when I put the
following formula in the Summary cell

=AVERAGEIF(Sheet1:Sheet8!D12,"35")

Any thoughts, ideas, suggestions??

Thankds