Hi Emece

In F2 enter =B2
In G2
=INDEX(A:A,MATCH($F2,B:B,0))
In H2
=IF(COUNTIF(D:D,F2),INDEX(C:C,MATCH($F2,D:D,0)),"" )

Copy F2:H2 down the sheet as far as required.
--
Regards
Roger Govier

Emece wrote:
Hi. I have the following data in a worksheet:

A B
DATE NUMBER
05/15/2010 321
05/16/2010 558
05/17/2010 665
05/18/2010 262

C D
DATE NUMBER
06/10/2010 321
06/11/2010 558
06/12/2010 665
06/13/2010 262

This is data that I import from a company application, and as you can see, a
number can have more than one date associated. I need to obtain in another
range, the number (only once) and the dates associated to it. How can I do
this comparation and filtering?

Hope it is clear enough

Thanks in advance.

Regards.
Emece.-