Hmm, not really sure what's wrong. Do you get any error messages? Or maybe
no messages at all but just no highlights in column D? Can you post a few
sample resulting values for column D? Also try opening the condition format
pop up again while you're in one of the cells in column D, what do you see?
That's all the questions I can think of for now.

-Simon

"HERNAN" wrote:

Thank you so much,... but is not working I did it exactly as you told me to.

"SimonCC" wrote:

In cell D1 put in the formula:
="A"&A1&"C"&C1
Copy the formula down as far as you have data.

Then with column D selected, go to Format | Conditional Formatting.
Select Formula Is for the dropdown box.
Put =COUNTIF(D:D,D1)1 in the formula box.
Click Format button and pick a color in the Patterns tab.

All the duplicte ones should then be highlighted in column D.

-Simon

"HERNAN" wrote:

I have this:
A B C
1 189 xxx $1.5
2 001 xxx $8.0
3 189 xxx $1.5
4 189 xxx $2.0

I just want to know when only column A and column C have the same numbers,
not just one column;... but both have to match. On this case would be Row # 3
the one that is duplicate and I wanted to find it.
Thank you so much!!!!!