Another thought ..

Assuming key data in cols A to C within rows 2 to 100
with rows containing any blank cells within cols A to C to be disregarded

Place in D2:
=IF(COUNTBLANK(A2:C2)<0,"",IF(SUMPRODUCT(($A$2:$A $100=A2)*($B$2:$B$100=B2)*($C$2:$C$100=C2))1,"X", ""))
Copy D2 down to D100. Col D will flag "X" for all lines with duplicates,
inclusive of the 1st occurrences. You could then easily apply autofilter on
D1 to filter out all these cases.

If you want to flag only the duplicate lines (ie leaving out the 1st
occurrences), use instead in D2:
=IF(COUNTBLANK(A2:C2)<0,"",IF(SUMPRODUCT(($A$2:A2 =A2)*($B$2:B2=B2)*($C$2:C2=C2))1,"X",""))
--
Max
Singapore
http://savefile.com/projects/236895
xdemechanik
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"TnT Tech Man" wrote:
I am trying to identify rows in a worksheet that have duplicate values in a
combination of three cells that should be unique in the worksheet.